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dir.c
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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2008 Miklos Szeredi <[email protected]>
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/moduleparam.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>
#include <linux/security.h>
#include <linux/types.h>
#include <linux/kernel.h>
static bool __read_mostly allow_sys_admin_access;
module_param(allow_sys_admin_access, bool, 0644);
MODULE_PARM_DESC(allow_sys_admin_access,
"Allow users with CAP_SYS_ADMIN in initial userns to bypass allow_other access check");
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);
}
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_EXCL | LOOKUP_REVAL | LOOKUP_RENAME_TARGET))) {
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 vfsmount *mnt;
struct fuse_inode *mp_fi = get_fuse_inode(d_inode(path->dentry));
fsc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry);
if (IS_ERR(fsc))
return ERR_CAST(fsc);
/* Pass the FUSE inode of the mount for fuse_get_tree_submount() */
fsc->fs_private = mp_fi;
/* Create the submount */
mnt = fc_mount(fsc);
if (!IS_ERR(mnt))
mntget(mnt);
put_fs_context(fsc);
return mnt;
}
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,
};
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);
}
static int get_security_context(struct dentry *entry, umode_t mode,
void **security_ctx, u32 *security_ctxlen)
{
struct fuse_secctx *fctx;
struct fuse_secctx_header *header;
void *ctx = NULL, *ptr;
u32 ctxlen, total_len = sizeof(*header);
int err, nr_ctx = 0;
const char *name;
size_t namelen;
err = security_dentry_init_security(entry, mode, &entry->d_name,
&name, &ctx, &ctxlen);
if (err) {
if (err != -EOPNOTSUPP)
goto out_err;
/* No LSM is supporting this security hook. Ignore error */
ctxlen = 0;
ctx = NULL;
}
if (ctxlen) {
nr_ctx = 1;
namelen = strlen(name) + 1;
err = -EIO;
if (WARN_ON(namelen > XATTR_NAME_MAX + 1 || ctxlen > S32_MAX))
goto out_err;
total_len += FUSE_REC_ALIGN(sizeof(*fctx) + namelen + ctxlen);
}
err = -ENOMEM;
header = ptr = kzalloc(total_len, GFP_KERNEL);
if (!ptr)
goto out_err;
header->nr_secctx = nr_ctx;
header->size = total_len;
ptr += sizeof(*header);
if (nr_ctx) {
fctx = ptr;
fctx->size = ctxlen;
ptr += sizeof(*fctx);
strcpy(ptr, name);
ptr += namelen;
memcpy(ptr, ctx, ctxlen);
}
*security_ctxlen = total_len;
*security_ctx = header;
err = 0;
out_err:
kfree(ctx);
return 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 int flags,
umode_t mode, u32 opcode)
{
int err;
struct inode *inode;
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;
void *security_ctx = NULL;
u32 security_ctxlen;
bool trunc = flags & O_TRUNC;
/* 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();
if (fm->fc->handle_killpriv_v2 && trunc &&
!(flags & O_EXCL) && !capable(CAP_FSETID)) {
inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
}
args.opcode = opcode;
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;
if (fm->fc->init_security) {
err = get_security_context(entry, mode, &security_ctx,
&security_ctxlen);
if (err)
goto out_put_forget_req;
args.in_numargs = 3;
args.in_args[2].size = security_ctxlen;
args.in_args[2].value = security_ctx;
}
err = fuse_simple_request(fm, &args);
kfree(security_ctx);
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;
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);
if (fm->fc->atomic_o_trunc && trunc)
truncate_pagecache(inode, 0);
else if (!(ff->open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages2(inode->i_mapping);
}
return err;
out_free_ff:
fuse_file_free(ff);
out_put_forget_req:
kfree(forget);
out_err:
return err;
}
static int fuse_mknod(struct mnt_idmap *, 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, FUSE_CREATE);
if (err == -ENOSYS) {
fc->no_create = 1;
goto mknod;
}
out_dput:
dput(res);
return err;
mknod:
err = fuse_mknod(&nop_mnt_idmap, 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;
void *security_ctx = NULL;
u32 security_ctxlen;
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;
if (fm->fc->init_security && args->opcode != FUSE_LINK) {
err = get_security_context(entry, mode, &security_ctx,
&security_ctxlen);
if (err)
goto out_put_forget_req;
BUG_ON(args->in_numargs != 2);
args->in_numargs = 3;
args->in_args[2].size = security_ctxlen;
args->in_args[2].value = security_ctx;
}
err = fuse_simple_request(fm, args);
kfree(security_ctx);
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 mnt_idmap *idmap, 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 mnt_idmap *idmap, struct inode *dir,
struct dentry *entry, umode_t mode, bool excl)
{
return fuse_mknod(&nop_mnt_idmap, dir, entry, mode, 0);
}
static int fuse_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct file *file, umode_t mode)
{
struct fuse_conn *fc = get_fuse_conn(dir);
int err;
if (fc->no_tmpfile)
return -EOPNOTSUPP;
err = fuse_create_open(dir, file->f_path.dentry, file, file->f_flags, mode, FUSE_TMPFILE);
if (err == -ENOSYS) {
fc->no_tmpfile = 1;
err = -EOPNOTSUPP;
}
return err;
}
static int fuse_mkdir(struct mnt_idmap *idmap, 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 mnt_idmap *idmap, 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);
}
static void fuse_update_ctime_in_cache(struct inode *inode)
{
if (!IS_NOCMTIME(inode)) {
inode->i_ctime = current_time(inode);
mark_inode_dirty_sync(inode);
fuse_flush_time_update(inode);
}
}
void fuse_update_ctime(struct inode *inode)
{
fuse_invalidate_attr_mask(inode, STATX_CTIME);
fuse_update_ctime_in_cache(inode);
}
static void fuse_entry_unlinked(struct dentry *entry)
{
struct inode *inode = d_inode(entry);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
/*
* 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 (S_ISDIR(inode->i_mode))
clear_nlink(inode);
else if (inode->i_nlink > 0)
drop_nlink(inode);
spin_unlock(&fi->lock);
fuse_invalidate_entry_cache(entry);
fuse_update_ctime(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) {
fuse_dir_changed(dir);
fuse_entry_unlinked(entry);
} 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) {
fuse_dir_changed(dir);
fuse_entry_unlinked(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_update_ctime(d_inode(oldent));
if (flags & RENAME_EXCHANGE)
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_entry_unlinked(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;
}