1 files changed, 706 insertions, 0 deletions

diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c
new file mode 100644
index 000000000000..f41f8d6108ce
--- /dev/null
+++ b/fs/smb/server/vfs_cache.c
@@ -0,0 +1,706 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
+ * Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "glob.h"
+#include "vfs_cache.h"
+#include "oplock.h"
+#include "vfs.h"
+#include "connection.h"
+#include "mgmt/tree_connect.h"
+#include "mgmt/user_session.h"
+#include "smb_common.h"
+
+#define S_DEL_PENDING			1
+#define S_DEL_ON_CLS			2
+#define S_DEL_ON_CLS_STREAM		8
+
+static unsigned int inode_hash_mask __read_mostly;
+static unsigned int inode_hash_shift __read_mostly;
+static struct hlist_head *inode_hashtable __read_mostly;
+static DEFINE_RWLOCK(inode_hash_lock);
+
+static struct ksmbd_file_table global_ft;
+static atomic_long_t fd_limit;
+static struct kmem_cache *filp_cache;
+
+void ksmbd_set_fd_limit(unsigned long limit)
+{
+	limit = min(limit, get_max_files());
+	atomic_long_set(&fd_limit, limit);
+}
+
+static bool fd_limit_depleted(void)
+{
+	long v = atomic_long_dec_return(&fd_limit);
+
+	if (v >= 0)
+		return false;
+	atomic_long_inc(&fd_limit);
+	return true;
+}
+
+static void fd_limit_close(void)
+{
+	atomic_long_inc(&fd_limit);
+}
+
+/*
+ * INODE hash
+ */
+
+static unsigned long inode_hash(struct super_block *sb, unsigned long hashval)
+{
+	unsigned long tmp;
+
+	tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
+		L1_CACHE_BYTES;
+	tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> inode_hash_shift);
+	return tmp & inode_hash_mask;
+}
+
+static struct ksmbd_inode *__ksmbd_inode_lookup(struct inode *inode)
+{
+	struct hlist_head *head = inode_hashtable +
+		inode_hash(inode->i_sb, inode->i_ino);
+	struct ksmbd_inode *ci = NULL, *ret_ci = NULL;
+
+	hlist_for_each_entry(ci, head, m_hash) {
+		if (ci->m_inode == inode) {
+			if (atomic_inc_not_zero(&ci->m_count))
+				ret_ci = ci;
+			break;
+		}
+	}
+	return ret_ci;
+}
+
+static struct ksmbd_inode *ksmbd_inode_lookup(struct ksmbd_file *fp)
+{
+	return __ksmbd_inode_lookup(file_inode(fp->filp));
+}
+
+static struct ksmbd_inode *ksmbd_inode_lookup_by_vfsinode(struct inode *inode)
+{
+	struct ksmbd_inode *ci;
+
+	read_lock(&inode_hash_lock);
+	ci = __ksmbd_inode_lookup(inode);
+	read_unlock(&inode_hash_lock);
+	return ci;
+}
+
+int ksmbd_query_inode_status(struct inode *inode)
+{
+	struct ksmbd_inode *ci;
+	int ret = KSMBD_INODE_STATUS_UNKNOWN;
+
+	read_lock(&inode_hash_lock);
+	ci = __ksmbd_inode_lookup(inode);
+	if (ci) {
+		ret = KSMBD_INODE_STATUS_OK;
+		if (ci->m_flags & S_DEL_PENDING)
+			ret = KSMBD_INODE_STATUS_PENDING_DELETE;
+		atomic_dec(&ci->m_count);
+	}
+	read_unlock(&inode_hash_lock);
+	return ret;
+}
+
+bool ksmbd_inode_pending_delete(struct ksmbd_file *fp)
+{
+	return (fp->f_ci->m_flags & S_DEL_PENDING);
+}
+
+void ksmbd_set_inode_pending_delete(struct ksmbd_file *fp)
+{
+	fp->f_ci->m_flags |= S_DEL_PENDING;
+}
+
+void ksmbd_clear_inode_pending_delete(struct ksmbd_file *fp)
+{
+	fp->f_ci->m_flags &= ~S_DEL_PENDING;
+}
+
+void ksmbd_fd_set_delete_on_close(struct ksmbd_file *fp,
+				  int file_info)
+{
+	if (ksmbd_stream_fd(fp)) {
+		fp->f_ci->m_flags |= S_DEL_ON_CLS_STREAM;
+		return;
+	}
+
+	fp->f_ci->m_flags |= S_DEL_ON_CLS;
+}
+
+static void ksmbd_inode_hash(struct ksmbd_inode *ci)
+{
+	struct hlist_head *b = inode_hashtable +
+		inode_hash(ci->m_inode->i_sb, ci->m_inode->i_ino);
+
+	hlist_add_head(&ci->m_hash, b);
+}
+
+static void ksmbd_inode_unhash(struct ksmbd_inode *ci)
+{
+	write_lock(&inode_hash_lock);
+	hlist_del_init(&ci->m_hash);
+	write_unlock(&inode_hash_lock);
+}
+
+static int ksmbd_inode_init(struct ksmbd_inode *ci, struct ksmbd_file *fp)
+{
+	ci->m_inode = file_inode(fp->filp);
+	atomic_set(&ci->m_count, 1);
+	atomic_set(&ci->op_count, 0);
+	atomic_set(&ci->sop_count, 0);
+	ci->m_flags = 0;
+	ci->m_fattr = 0;
+	INIT_LIST_HEAD(&ci->m_fp_list);
+	INIT_LIST_HEAD(&ci->m_op_list);
+	rwlock_init(&ci->m_lock);
+	return 0;
+}
+
+static struct ksmbd_inode *ksmbd_inode_get(struct ksmbd_file *fp)
+{
+	struct ksmbd_inode *ci, *tmpci;
+	int rc;
+
+	read_lock(&inode_hash_lock);
+	ci = ksmbd_inode_lookup(fp);
+	read_unlock(&inode_hash_lock);
+	if (ci)
+		return ci;
+
+	ci = kmalloc(sizeof(struct ksmbd_inode), GFP_KERNEL);
+	if (!ci)
+		return NULL;
+
+	rc = ksmbd_inode_init(ci, fp);
+	if (rc) {
+		pr_err("inode initialized failed\n");
+		kfree(ci);
+		return NULL;
+	}
+
+	write_lock(&inode_hash_lock);
+	tmpci = ksmbd_inode_lookup(fp);
+	if (!tmpci) {
+		ksmbd_inode_hash(ci);
+	} else {
+		kfree(ci);
+		ci = tmpci;
+	}
+	write_unlock(&inode_hash_lock);
+	return ci;
+}
+
+static void ksmbd_inode_free(struct ksmbd_inode *ci)
+{
+	ksmbd_inode_unhash(ci);
+	kfree(ci);
+}
+
+static void ksmbd_inode_put(struct ksmbd_inode *ci)
+{
+	if (atomic_dec_and_test(&ci->m_count))
+		ksmbd_inode_free(ci);
+}
+
+int __init ksmbd_inode_hash_init(void)
+{
+	unsigned int loop;
+	unsigned long numentries = 16384;
+	unsigned long bucketsize = sizeof(struct hlist_head);
+	unsigned long size;
+
+	inode_hash_shift = ilog2(numentries);
+	inode_hash_mask = (1 << inode_hash_shift) - 1;
+
+	size = bucketsize << inode_hash_shift;
+
+	/* init master fp hash table */
+	inode_hashtable = vmalloc(size);
+	if (!inode_hashtable)
+		return -ENOMEM;
+
+	for (loop = 0; loop < (1U << inode_hash_shift); loop++)
+		INIT_HLIST_HEAD(&inode_hashtable[loop]);
+	return 0;
+}
+
+void ksmbd_release_inode_hash(void)
+{
+	vfree(inode_hashtable);
+}
+
+static void __ksmbd_inode_close(struct ksmbd_file *fp)
+{
+	struct ksmbd_inode *ci = fp->f_ci;
+	int err;
+	struct file *filp;
+
+	filp = fp->filp;
+	if (ksmbd_stream_fd(fp) && (ci->m_flags & S_DEL_ON_CLS_STREAM)) {
+		ci->m_flags &= ~S_DEL_ON_CLS_STREAM;
+		err = ksmbd_vfs_remove_xattr(file_mnt_idmap(filp),
+					     &filp->f_path,
+					     fp->stream.name);
+		if (err)
+			pr_err("remove xattr failed : %s\n",
+			       fp->stream.name);
+	}
+
+	if (atomic_dec_and_test(&ci->m_count)) {
+		write_lock(&ci->m_lock);
+		if (ci->m_flags & (S_DEL_ON_CLS | S_DEL_PENDING)) {
+			ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
+			write_unlock(&ci->m_lock);
+			ksmbd_vfs_unlink(filp);
+			write_lock(&ci->m_lock);
+		}
+		write_unlock(&ci->m_lock);
+
+		ksmbd_inode_free(ci);
+	}
+}
+
+static void __ksmbd_remove_durable_fd(struct ksmbd_file *fp)
+{
+	if (!has_file_id(fp->persistent_id))
+		return;
+
+	write_lock(&global_ft.lock);
+	idr_remove(global_ft.idr, fp->persistent_id);
+	write_unlock(&global_ft.lock);
+}
+
+static void __ksmbd_remove_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
+{
+	if (!has_file_id(fp->volatile_id))
+		return;
+
+	write_lock(&fp->f_ci->m_lock);
+	list_del_init(&fp->node);
+	write_unlock(&fp->f_ci->m_lock);
+
+	write_lock(&ft->lock);
+	idr_remove(ft->idr, fp->volatile_id);
+	write_unlock(&ft->lock);
+}
+
+static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
+{
+	struct file *filp;
+	struct ksmbd_lock *smb_lock, *tmp_lock;
+
+	fd_limit_close();
+	__ksmbd_remove_durable_fd(fp);
+	__ksmbd_remove_fd(ft, fp);
+
+	close_id_del_oplock(fp);
+	filp = fp->filp;
+
+	__ksmbd_inode_close(fp);
+	if (!IS_ERR_OR_NULL(filp))
+		fput(filp);
+
+	/* because the reference count of fp is 0, it is guaranteed that
+	 * there are not accesses to fp->lock_list.
+	 */
+	list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) {
+		spin_lock(&fp->conn->llist_lock);
+		list_del(&smb_lock->clist);
+		spin_unlock(&fp->conn->llist_lock);
+
+		list_del(&smb_lock->flist);
+		locks_free_lock(smb_lock->fl);
+		kfree(smb_lock);
+	}
+
+	if (ksmbd_stream_fd(fp))
+		kfree(fp->stream.name);
+	kmem_cache_free(filp_cache, fp);
+}
+
+static struct ksmbd_file *ksmbd_fp_get(struct ksmbd_file *fp)
+{
+	if (!atomic_inc_not_zero(&fp->refcount))
+		return NULL;
+	return fp;
+}
+
+static struct ksmbd_file *__ksmbd_lookup_fd(struct ksmbd_file_table *ft,
+					    u64 id)
+{
+	struct ksmbd_file *fp;
+
+	if (!has_file_id(id))
+		return NULL;
+
+	read_lock(&ft->lock);
+	fp = idr_find(ft->idr, id);
+	if (fp)
+		fp = ksmbd_fp_get(fp);
+	read_unlock(&ft->lock);
+	return fp;
+}
+
+static void __put_fd_final(struct ksmbd_work *work, struct ksmbd_file *fp)
+{
+	__ksmbd_close_fd(&work->sess->file_table, fp);
+	atomic_dec(&work->conn->stats.open_files_count);
+}
+
+static void set_close_state_blocked_works(struct ksmbd_file *fp)
+{
+	struct ksmbd_work *cancel_work;
+
+	spin_lock(&fp->f_lock);
+	list_for_each_entry(cancel_work, &fp->blocked_works,
+				 fp_entry) {
+		cancel_work->state = KSMBD_WORK_CLOSED;
+		cancel_work->cancel_fn(cancel_work->cancel_argv);
+	}
+	spin_unlock(&fp->f_lock);
+}
+
+int ksmbd_close_fd(struct ksmbd_work *work, u64 id)
+{
+	struct ksmbd_file	*fp;
+	struct ksmbd_file_table	*ft;
+
+	if (!has_file_id(id))
+		return 0;
+
+	ft = &work->sess->file_table;
+	read_lock(&ft->lock);
+	fp = idr_find(ft->idr, id);
+	if (fp) {
+		set_close_state_blocked_works(fp);
+
+		if (!atomic_dec_and_test(&fp->refcount))
+			fp = NULL;
+	}
+	read_unlock(&ft->lock);
+
+	if (!fp)
+		return -EINVAL;
+
+	__put_fd_final(work, fp);
+	return 0;
+}
+
+void ksmbd_fd_put(struct ksmbd_work *work, struct ksmbd_file *fp)
+{
+	if (!fp)
+		return;
+
+	if (!atomic_dec_and_test(&fp->refcount))
+		return;
+	__put_fd_final(work, fp);
+}
+
+static bool __sanity_check(struct ksmbd_tree_connect *tcon, struct ksmbd_file *fp)
+{
+	if (!fp)
+		return false;
+	if (fp->tcon != tcon)
+		return false;
+	return true;
+}
+
+struct ksmbd_file *ksmbd_lookup_foreign_fd(struct ksmbd_work *work, u64 id)
+{
+	return __ksmbd_lookup_fd(&work->sess->file_table, id);
+}
+
+struct ksmbd_file *ksmbd_lookup_fd_fast(struct ksmbd_work *work, u64 id)
+{
+	struct ksmbd_file *fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
+
+	if (__sanity_check(work->tcon, fp))
+		return fp;
+
+	ksmbd_fd_put(work, fp);
+	return NULL;
+}
+
+struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
+					u64 pid)
+{
+	struct ksmbd_file *fp;
+
+	if (!has_file_id(id)) {
+		id = work->compound_fid;
+		pid = work->compound_pfid;
+	}
+
+	fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
+	if (!__sanity_check(work->tcon, fp)) {
+		ksmbd_fd_put(work, fp);
+		return NULL;
+	}
+	if (fp->persistent_id != pid) {
+		ksmbd_fd_put(work, fp);
+		return NULL;
+	}
+	return fp;
+}
+
+struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
+{
+	return __ksmbd_lookup_fd(&global_ft, id);
+}
+
+struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid)
+{
+	struct ksmbd_file	*fp = NULL;
+	unsigned int		id;
+
+	read_lock(&global_ft.lock);
+	idr_for_each_entry(global_ft.idr, fp, id) {
+		if (!memcmp(fp->create_guid,
+			    cguid,
+			    SMB2_CREATE_GUID_SIZE)) {
+			fp = ksmbd_fp_get(fp);
+			break;
+		}
+	}
+	read_unlock(&global_ft.lock);
+
+	return fp;
+}
+
+struct ksmbd_file *ksmbd_lookup_fd_inode(struct inode *inode)
+{
+	struct ksmbd_file	*lfp;
+	struct ksmbd_inode	*ci;
+
+	ci = ksmbd_inode_lookup_by_vfsinode(inode);
+	if (!ci)
+		return NULL;
+
+	read_lock(&ci->m_lock);
+	list_for_each_entry(lfp, &ci->m_fp_list, node) {
+		if (inode == file_inode(lfp->filp)) {
+			atomic_dec(&ci->m_count);
+			lfp = ksmbd_fp_get(lfp);
+			read_unlock(&ci->m_lock);
+			return lfp;
+		}
+	}
+	atomic_dec(&ci->m_count);
+	read_unlock(&ci->m_lock);
+	return NULL;
+}
+
+#define OPEN_ID_TYPE_VOLATILE_ID	(0)
+#define OPEN_ID_TYPE_PERSISTENT_ID	(1)
+
+static void __open_id_set(struct ksmbd_file *fp, u64 id, int type)
+{
+	if (type == OPEN_ID_TYPE_VOLATILE_ID)
+		fp->volatile_id = id;
+	if (type == OPEN_ID_TYPE_PERSISTENT_ID)
+		fp->persistent_id = id;
+}
+
+static int __open_id(struct ksmbd_file_table *ft, struct ksmbd_file *fp,
+		     int type)
+{
+	u64			id = 0;
+	int			ret;
+
+	if (type == OPEN_ID_TYPE_VOLATILE_ID && fd_limit_depleted()) {
+		__open_id_set(fp, KSMBD_NO_FID, type);
+		return -EMFILE;
+	}
+
+	idr_preload(GFP_KERNEL);
+	write_lock(&ft->lock);
+	ret = idr_alloc_cyclic(ft->idr, fp, 0, INT_MAX - 1, GFP_NOWAIT);
+	if (ret >= 0) {
+		id = ret;
+		ret = 0;
+	} else {
+		id = KSMBD_NO_FID;
+		fd_limit_close();
+	}
+
+	__open_id_set(fp, id, type);
+	write_unlock(&ft->lock);
+	idr_preload_end();
+	return ret;
+}
+
+unsigned int ksmbd_open_durable_fd(struct ksmbd_file *fp)
+{
+	__open_id(&global_ft, fp, OPEN_ID_TYPE_PERSISTENT_ID);
+	return fp->persistent_id;
+}
+
+struct ksmbd_file *ksmbd_open_fd(struct ksmbd_work *work, struct file *filp)
+{
+	struct ksmbd_file *fp;
+	int ret;
+
+	fp = kmem_cache_zalloc(filp_cache, GFP_KERNEL);
+	if (!fp) {
+		pr_err("Failed to allocate memory\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	INIT_LIST_HEAD(&fp->blocked_works);
+	INIT_LIST_HEAD(&fp->node);
+	INIT_LIST_HEAD(&fp->lock_list);
+	spin_lock_init(&fp->f_lock);
+	atomic_set(&fp->refcount, 1);
+
+	fp->filp		= filp;
+	fp->conn		= work->conn;
+	fp->tcon		= work->tcon;
+	fp->volatile_id		= KSMBD_NO_FID;
+	fp->persistent_id	= KSMBD_NO_FID;
+	fp->f_ci		= ksmbd_inode_get(fp);
+
+	if (!fp->f_ci) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+
+	ret = __open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
+	if (ret) {
+		ksmbd_inode_put(fp->f_ci);
+		goto err_out;
+	}
+
+	atomic_inc(&work->conn->stats.open_files_count);
+	return fp;
+
+err_out:
+	kmem_cache_free(filp_cache, fp);
+	return ERR_PTR(ret);
+}
+
+static int
+__close_file_table_ids(struct ksmbd_file_table *ft,
+		       struct ksmbd_tree_connect *tcon,
+		       bool (*skip)(struct ksmbd_tree_connect *tcon,
+				    struct ksmbd_file *fp))
+{
+	unsigned int			id;
+	struct ksmbd_file		*fp;
+	int				num = 0;
+
+	idr_for_each_entry(ft->idr, fp, id) {
+		if (skip(tcon, fp))
+			continue;
+
+		set_close_state_blocked_works(fp);
+
+		if (!atomic_dec_and_test(&fp->refcount))
+			continue;
+		__ksmbd_close_fd(ft, fp);
+		num++;
+	}
+	return num;
+}
+
+static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
+			       struct ksmbd_file *fp)
+{
+	return fp->tcon != tcon;
+}
+
+static bool session_fd_check(struct ksmbd_tree_connect *tcon,
+			     struct ksmbd_file *fp)
+{
+	return false;
+}
+
+void ksmbd_close_tree_conn_fds(struct ksmbd_work *work)
+{
+	int num = __close_file_table_ids(&work->sess->file_table,
+					 work->tcon,
+					 tree_conn_fd_check);
+
+	atomic_sub(num, &work->conn->stats.open_files_count);
+}
+
+void ksmbd_close_session_fds(struct ksmbd_work *work)
+{
+	int num = __close_file_table_ids(&work->sess->file_table,
+					 work->tcon,
+					 session_fd_check);
+
+	atomic_sub(num, &work->conn->stats.open_files_count);
+}
+
+int ksmbd_init_global_file_table(void)
+{
+	return ksmbd_init_file_table(&global_ft);
+}
+
+void ksmbd_free_global_file_table(void)
+{
+	struct ksmbd_file	*fp = NULL;
+	unsigned int		id;
+
+	idr_for_each_entry(global_ft.idr, fp, id) {
+		__ksmbd_remove_durable_fd(fp);
+		kmem_cache_free(filp_cache, fp);
+	}
+
+	ksmbd_destroy_file_table(&global_ft);
+}
+
+int ksmbd_init_file_table(struct ksmbd_file_table *ft)
+{
+	ft->idr = kzalloc(sizeof(struct idr), GFP_KERNEL);
+	if (!ft->idr)
+		return -ENOMEM;
+
+	idr_init(ft->idr);
+	rwlock_init(&ft->lock);
+	return 0;
+}
+
+void ksmbd_destroy_file_table(struct ksmbd_file_table *ft)
+{
+	if (!ft->idr)
+		return;
+
+	__close_file_table_ids(ft, NULL, session_fd_check);
+	idr_destroy(ft->idr);
+	kfree(ft->idr);
+	ft->idr = NULL;
+}
+
+int ksmbd_init_file_cache(void)
+{
+	filp_cache = kmem_cache_create("ksmbd_file_cache",
+				       sizeof(struct ksmbd_file), 0,
+				       SLAB_HWCACHE_ALIGN, NULL);
+	if (!filp_cache)
+		goto out;
+
+	return 0;
+
+out:
+	pr_err("failed to allocate file cache\n");
+	return -ENOMEM;
+}
+
+void ksmbd_exit_file_cache(void)
+{
+	kmem_cache_destroy(filp_cache);
+}