#include <linux/sched.h>
#include <linux/namei.h>
-static inline unsigned long time_to_jiffies(unsigned long sec,
- unsigned long nsec)
+/*
+ * FUSE caches dentries and attributes with separate timeout. The
+ * time in jiffies until the dentry/attributes are valid is stored in
+ * dentry->d_time and fuse_inode->i_time respectively.
+ */
+
+/*
+ * Calculate the time in jiffies until a dentry/attributes are valid
+ */
+static unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec)
{
struct timespec ts = {sec, nsec};
return jiffies + timespec_to_jiffies(&ts);
}
+/*
+ * Set dentry and possibly attribute timeouts from the lookup/mk*
+ * replies
+ */
+static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o)
+{
+ entry->d_time = time_to_jiffies(o->entry_valid, o->entry_valid_nsec);
+ if (entry->d_inode)
+ get_fuse_inode(entry->d_inode)->i_time =
+ time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
+}
+
+/*
+ * 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)
+{
+ get_fuse_inode(inode)->i_time = jiffies - 1;
+}
+
+/*
+ * 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)
+ */
+static void fuse_invalidate_entry_cache(struct dentry *entry)
+{
+ entry->d_time = jiffies - 1;
+}
+
+/*
+ * 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_req *req, struct inode *dir,
struct dentry *entry,
struct fuse_entry_out *outarg)
req->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, struct nameidata *nd)
{
- if (!entry->d_inode || is_bad_inode(entry->d_inode))
+ struct inode *inode = entry->d_inode;
+
+ if (inode && is_bad_inode(inode))
return 0;
else if (time_after(jiffies, entry->d_time)) {
int err;
struct fuse_entry_out outarg;
- struct inode *inode = entry->d_inode;
- struct fuse_inode *fi = get_fuse_inode(inode);
- struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
+ struct fuse_conn *fc;
+ struct fuse_req *req;
+
+ /* Doesn't hurt to "reset" the validity timeout */
+ fuse_invalidate_entry_cache(entry);
+ if (!inode)
+ return 0;
+
+ fc = get_fuse_conn(inode);
+ req = fuse_get_request(fc);
if (!req)
return 0;
request_send(fc, req);
err = req->out.h.error;
if (!err) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
if (outarg.nodeid != get_node_id(inode)) {
fuse_send_forget(fc, req, outarg.nodeid, 1);
return 0;
return 0;
fuse_change_attributes(inode, &outarg.attr);
- entry->d_time = time_to_jiffies(outarg.entry_valid,
- outarg.entry_valid_nsec);
- fi->i_time = time_to_jiffies(outarg.attr_valid,
- outarg.attr_valid_nsec);
+ fuse_change_timeout(entry, &outarg);
}
return 1;
}
+/*
+ * Check if there's already a hashed alias of this directory inode.
+ * If yes, then lookup and mkdir must not create a new alias.
+ */
+static int dir_alias(struct inode *inode)
+{
+ if (S_ISDIR(inode->i_mode)) {
+ struct dentry *alias = d_find_alias(inode);
+ if (alias) {
+ dput(alias);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int invalid_nodeid(u64 nodeid)
+{
+ return !nodeid || nodeid == FUSE_ROOT_ID;
+}
+
static struct dentry_operations fuse_dentry_operations = {
.d_revalidate = fuse_dentry_revalidate,
};
-static int fuse_lookup_iget(struct inode *dir, struct dentry *entry,
- struct inode **inodep)
+static int valid_mode(int m)
+{
+ return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
+ S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
+}
+
+static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
+ struct nameidata *nd)
{
int err;
struct fuse_entry_out outarg;
struct fuse_req *req;
if (entry->d_name.len > FUSE_NAME_MAX)
- return -ENAMETOOLONG;
+ return ERR_PTR(-ENAMETOOLONG);
req = fuse_get_request(fc);
if (!req)
- return -EINTR;
+ return ERR_PTR(-EINTR);
fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req);
err = req->out.h.error;
- if (!err && (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID))
+ if (!err && ((outarg.nodeid && invalid_nodeid(outarg.nodeid)) ||
+ !valid_mode(outarg.attr.mode)))
err = -EIO;
- if (!err) {
+ if (!err && outarg.nodeid) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
&outarg.attr);
if (!inode) {
fuse_send_forget(fc, req, outarg.nodeid, 1);
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
}
}
fuse_put_request(fc, req);
if (err && err != -ENOENT)
- return err;
+ return ERR_PTR(err);
- if (inode) {
- struct fuse_inode *fi = get_fuse_inode(inode);
- entry->d_time = time_to_jiffies(outarg.entry_valid,
- outarg.entry_valid_nsec);
- fi->i_time = time_to_jiffies(outarg.attr_valid,
- outarg.attr_valid_nsec);
+ if (inode && dir_alias(inode)) {
+ iput(inode);
+ return ERR_PTR(-EIO);
}
-
+ d_add(entry, inode);
entry->d_op = &fuse_dentry_operations;
- *inodep = inode;
- return 0;
+ if (!err)
+ fuse_change_timeout(entry, &outarg);
+ else
+ fuse_invalidate_entry_cache(entry);
+ return NULL;
}
-void fuse_invalidate_attr(struct inode *inode)
+/*
+ * 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, int mode,
+ struct nameidata *nd)
{
- get_fuse_inode(inode)->i_time = jiffies - 1;
-}
+ int err;
+ struct inode *inode;
+ struct fuse_conn *fc = get_fuse_conn(dir);
+ struct fuse_req *req;
+ struct fuse_open_in inarg;
+ struct fuse_open_out outopen;
+ struct fuse_entry_out outentry;
+ struct fuse_file *ff;
+ struct file *file;
+ int flags = nd->intent.open.flags - 1;
+
+ err = -ENOSYS;
+ if (fc->no_create)
+ goto out;
-static void fuse_invalidate_entry(struct dentry *entry)
-{
- d_invalidate(entry);
- entry->d_time = jiffies - 1;
+ err = -EINTR;
+ req = fuse_get_request(fc);
+ if (!req)
+ goto out;
+
+ ff = fuse_file_alloc();
+ if (!ff)
+ goto out_put_request;
+
+ flags &= ~O_NOCTTY;
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.flags = flags;
+ inarg.mode = mode;
+ req->in.h.opcode = FUSE_CREATE;
+ req->in.h.nodeid = get_node_id(dir);
+ req->inode = dir;
+ req->in.numargs = 2;
+ req->in.args[0].size = sizeof(inarg);
+ req->in.args[0].value = &inarg;
+ req->in.args[1].size = entry->d_name.len + 1;
+ req->in.args[1].value = entry->d_name.name;
+ req->out.numargs = 2;
+ req->out.args[0].size = sizeof(outentry);
+ req->out.args[0].value = &outentry;
+ req->out.args[1].size = sizeof(outopen);
+ req->out.args[1].value = &outopen;
+ request_send(fc, req);
+ err = req->out.h.error;
+ if (err) {
+ if (err == -ENOSYS)
+ fc->no_create = 1;
+ goto out_free_ff;
+ }
+
+ err = -EIO;
+ if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
+ goto out_free_ff;
+
+ inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
+ &outentry.attr);
+ err = -ENOMEM;
+ if (!inode) {
+ flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
+ ff->fh = outopen.fh;
+ /* Special release, with inode = NULL, this will
+ trigger a 'forget' request when the release is
+ complete */
+ fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);
+ goto out_put_request;
+ }
+ fuse_put_request(fc, req);
+ d_instantiate(entry, inode);
+ fuse_change_timeout(entry, &outentry);
+ file = lookup_instantiate_filp(nd, entry, generic_file_open);
+ if (IS_ERR(file)) {
+ ff->fh = outopen.fh;
+ fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);
+ return PTR_ERR(file);
+ }
+ fuse_finish_open(inode, file, ff, &outopen);
+ return 0;
+
+ out_free_ff:
+ fuse_file_free(ff);
+ out_put_request:
+ fuse_put_request(fc, req);
+ out:
+ return err;
}
+/*
+ * Code shared between mknod, mkdir, symlink and link
+ */
static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
struct inode *dir, struct dentry *entry,
int mode)
{
struct fuse_entry_out outarg;
struct inode *inode;
- struct fuse_inode *fi;
int err;
req->in.h.nodeid = get_node_id(dir);
fuse_put_request(fc, req);
return err;
}
- if (!outarg.nodeid || outarg.nodeid == FUSE_ROOT_ID) {
- fuse_put_request(fc, req);
- return -EIO;
- }
+ err = -EIO;
+ if (invalid_nodeid(outarg.nodeid))
+ goto out_put_request;
+
+ if ((outarg.attr.mode ^ mode) & S_IFMT)
+ goto out_put_request;
+
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
&outarg.attr);
if (!inode) {
}
fuse_put_request(fc, req);
- /* Don't allow userspace to do really stupid things... */
- if ((inode->i_mode ^ mode) & S_IFMT) {
+ if (dir_alias(inode)) {
iput(inode);
return -EIO;
}
- entry->d_time = time_to_jiffies(outarg.entry_valid,
- outarg.entry_valid_nsec);
-
- fi = get_fuse_inode(inode);
- fi->i_time = time_to_jiffies(outarg.attr_valid,
- outarg.attr_valid_nsec);
-
d_instantiate(entry, inode);
+ fuse_change_timeout(entry, &outarg);
fuse_invalidate_attr(dir);
return 0;
+
+ out_put_request:
+ fuse_put_request(fc, req);
+ return err;
}
static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
struct nameidata *nd)
{
+ if (nd && (nd->flags & LOOKUP_CREATE)) {
+ int err = fuse_create_open(dir, entry, mode, nd);
+ if (err != -ENOSYS)
+ return err;
+ /* Fall back on mknod */
+ }
return fuse_mknod(dir, entry, mode, 0);
}
{
struct fuse_conn *fc = get_fuse_conn(dir);
unsigned len = strlen(link) + 1;
- struct fuse_req *req;
-
- if (len > FUSE_SYMLINK_MAX)
- return -ENAMETOOLONG;
-
- req = fuse_get_request(fc);
+ struct fuse_req *req = fuse_get_request(fc);
if (!req)
return -EINTR;
inode->i_nlink = 0;
fuse_invalidate_attr(inode);
fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
if (!err) {
entry->d_inode->i_nlink = 0;
fuse_invalidate_attr(dir);
+ fuse_invalidate_entry_cache(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
fuse_invalidate_attr(olddir);
if (olddir != newdir)
fuse_invalidate_attr(newdir);
+
+ /* newent will end up negative */
+ if (newent->d_inode)
+ fuse_invalidate_entry_cache(newent);
} else if (err == -EINTR) {
/* If request was interrupted, DEITY only knows if the
rename actually took place. If the invalidation
return 0;
}
+/*
+ * Check whether the inode attributes are still valid
+ *
+ * If the attribute validity timeout has expired, then fetch the fresh
+ * attributes with a 'getattr' request
+ *
+ * I'm not sure why cached attributes are never returned for the root
+ * inode, this is probably being too cautious.
+ */
static int fuse_revalidate(struct dentry *entry)
{
struct inode *inode = entry->d_inode;
return fuse_do_getattr(inode);
}
+static int fuse_access(struct inode *inode, int mask)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ struct fuse_access_in inarg;
+ int err;
+
+ if (fc->no_access)
+ return 0;
+
+ req = fuse_get_request(fc);
+ if (!req)
+ return -EINTR;
+
+ memset(&inarg, 0, sizeof(inarg));
+ inarg.mask = mask;
+ req->in.h.opcode = FUSE_ACCESS;
+ req->in.h.nodeid = get_node_id(inode);
+ req->inode = inode;
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(inarg);
+ req->in.args[0].value = &inarg;
+ request_send(fc, req);
+ err = req->out.h.error;
+ fuse_put_request(fc, req);
+ if (err == -ENOSYS) {
+ fc->no_access = 1;
+ err = 0;
+ }
+ return err;
+}
+
+/*
+ * Check permission. The two basic access models of FUSE are:
+ *
+ * 1) Local access checking ('default_permissions' mount option) based
+ * on file mode. This is the plain old disk filesystem permission
+ * modell.
+ *
+ * 2) "Remote" access checking, where server is responsible for
+ * checking permission in each inode operation. An exception to this
+ * is if ->permission() was invoked from sys_access() in which case an
+ * access request is sent. Execute permission is still checked
+ * locally based on file mode.
+ */
static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd)
{
struct fuse_conn *fc = get_fuse_conn(inode);
err = generic_permission(inode, mask, NULL);
}
- /* FIXME: Need some mechanism to revoke permissions:
- currently if the filesystem suddenly changes the
- file mode, we will not be informed about it, and
- continue to allow access to the file/directory.
-
- This is actually not so grave, since the user can
- simply keep access to the file/directory anyway by
- keeping it open... */
+ /* Note: the opposite of the above test does not
+ exist. So if permissions are revoked this won't be
+ noticed immediately, only after the attribute
+ timeout has expired */
return err;
} else {
int mode = inode->i_mode;
if ((mask & MAY_EXEC) && !S_ISDIR(mode) && !(mode & S_IXUGO))
return -EACCES;
+
+ if (nd && (nd->flags & LOOKUP_ACCESS))
+ return fuse_access(inode, mask);
return 0;
}
}
return 0;
}
-static inline size_t fuse_send_readdir(struct fuse_req *req, struct file *file,
- struct inode *inode, loff_t pos,
- size_t count)
-{
- return fuse_send_read_common(req, file, inode, pos, count, 1);
-}
-
static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
{
int err;
struct page *page;
struct inode *inode = file->f_dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
- struct fuse_req *req = fuse_get_request(fc);
+ struct fuse_req *req;
+
+ if (is_bad_inode(inode))
+ return -EIO;
+
+ req = fuse_get_request(fc);
if (!req)
return -EINTR;
}
req->num_pages = 1;
req->pages[0] = page;
- nbytes = fuse_send_readdir(req, file, inode, file->f_pos, PAGE_SIZE);
+ fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);
+ request_send(fc, req);
+ nbytes = req->out.args[0].size;
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err)
return file ? fuse_fsync_common(file, de, datasync, 1) : 0;
}
-static unsigned iattr_to_fattr(struct iattr *iattr, struct fuse_attr *fattr)
+static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
{
unsigned ivalid = iattr->ia_valid;
- unsigned fvalid = 0;
-
- memset(fattr, 0, sizeof(*fattr));
if (ivalid & ATTR_MODE)
- fvalid |= FATTR_MODE, fattr->mode = iattr->ia_mode;
+ arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode;
if (ivalid & ATTR_UID)
- fvalid |= FATTR_UID, fattr->uid = iattr->ia_uid;
+ arg->valid |= FATTR_UID, arg->uid = iattr->ia_uid;
if (ivalid & ATTR_GID)
- fvalid |= FATTR_GID, fattr->gid = iattr->ia_gid;
+ arg->valid |= FATTR_GID, arg->gid = iattr->ia_gid;
if (ivalid & ATTR_SIZE)
- fvalid |= FATTR_SIZE, fattr->size = iattr->ia_size;
+ arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size;
/* You can only _set_ these together (they may change by themselves) */
if ((ivalid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME)) {
- fvalid |= FATTR_ATIME | FATTR_MTIME;
- fattr->atime = iattr->ia_atime.tv_sec;
- fattr->mtime = iattr->ia_mtime.tv_sec;
+ arg->valid |= FATTR_ATIME | FATTR_MTIME;
+ arg->atime = iattr->ia_atime.tv_sec;
+ arg->mtime = iattr->ia_mtime.tv_sec;
+ }
+ if (ivalid & ATTR_FILE) {
+ struct fuse_file *ff = iattr->ia_file->private_data;
+ arg->valid |= FATTR_FH;
+ arg->fh = ff->fh;
}
-
- return fvalid;
}
+/*
+ * Set attributes, and at the same time refresh them.
+ *
+ * Truncation is slightly complicated, because the 'truncate' request
+ * may fail, in which case we don't want to touch the mapping.
+ * vmtruncate() doesn't allow for this case. So do the rlimit
+ * checking by hand and call vmtruncate() only after the file has
+ * actually been truncated.
+ */
static int fuse_setattr(struct dentry *entry, struct iattr *attr)
{
struct inode *inode = entry->d_inode;
return -EINTR;
memset(&inarg, 0, sizeof(inarg));
- inarg.valid = iattr_to_fattr(attr, &inarg.attr);
+ iattr_to_fattr(attr, &inarg);
req->in.h.opcode = FUSE_SETATTR;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
return err;
}
-static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
- struct nameidata *nd)
-{
- struct inode *inode;
- int err = fuse_lookup_iget(dir, entry, &inode);
- if (err)
- return ERR_PTR(err);
- if (inode && S_ISDIR(inode->i_mode)) {
- /* Don't allow creating an alias to a directory */
- struct dentry *alias = d_find_alias(inode);
- if (alias) {
- dput(alias);
- iput(inode);
- return ERR_PTR(-EIO);
- }
- }
- d_add(entry, inode);
- return NULL;
-}
-
static int fuse_setxattr(struct dentry *entry, const char *name,
const void *value, size_t size, int flags)
{
struct fuse_setxattr_in inarg;
int err;
- if (size > FUSE_XATTR_SIZE_MAX)
- return -E2BIG;
-
if (fc->no_setxattr)
return -EOPNOTSUPP;
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