[Deepin-Kernel-SIG] [linux-6.6.y] [Upstream] exfat: Implement sops->shutdown and ioctl

fs/exfat/exfat_fs.h

@@ -10,6 +10,7 @@
 #include <linux/ratelimit.h>
 #include <linux/nls.h>
 #include <linux/blkdev.h>
+#include <uapi/linux/exfat.h>
 
 #define EXFAT_ROOT_INO		1
 
@@ -149,6 +150,9 @@ enum {
 #define DIR_CACHE_SIZE		\
 	(DIV_ROUND_UP(EXFAT_DEN_TO_B(ES_MAX_ENTRY_NUM), SECTOR_SIZE) + 1)
 
+/* Superblock flags */
+#define EXFAT_FLAGS_SHUTDOWN	1
+
 struct exfat_dentry_namebuf {
 	char *lfn;
 	int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */
@@ -265,6 +269,8 @@ struct exfat_sb_info {
 	unsigned int clu_srch_ptr; /* cluster search pointer */
 	unsigned int used_clusters; /* number of used clusters */
 
+	unsigned long s_exfat_flags; /* Exfat superblock flags */
+
 	struct mutex s_lock; /* superblock lock */
 	struct mutex bitmap_lock; /* bitmap lock */
 	struct exfat_mount_options options;
@@ -334,6 +340,11 @@ static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
 	return container_of(inode, struct exfat_inode_info, vfs_inode);
 }
 
+static inline int exfat_forced_shutdown(struct super_block *sb)
+{
+	return test_bit(EXFAT_FLAGS_SHUTDOWN, &EXFAT_SB(sb)->s_exfat_flags);
+}
+
 /*
  * If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
  * save ATTR_RO instead of ->i_mode.
@@ -459,6 +470,7 @@ int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
 				unsigned long arg);
+int exfat_force_shutdown(struct super_block *sb, u32 flags);
 
 /* namei.c */
 extern const struct dentry_operations exfat_dentry_ops;

fs/exfat/file.c

@@ -249,6 +249,9 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	unsigned int ia_valid;
 	int error;
 
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
 	if ((attr->ia_valid & ATTR_SIZE) &&
 	    attr->ia_size > i_size_read(inode)) {
 		error = exfat_cont_expand(inode, attr->ia_size);
@@ -343,11 +346,26 @@ static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
 	return 0;
 }
 
+static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg)
+{
+	u32 flags;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (get_user(flags, (__u32 __user *)arg))
+		return -EFAULT;
+
+	return exfat_force_shutdown(sb, flags);
+}
+
 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 
 	switch (cmd) {
+	case EXFAT_IOC_SHUTDOWN:
+		return exfat_ioctl_shutdown(inode->i_sb, arg);
 	case FITRIM:
 		return exfat_ioctl_fitrim(inode, arg);
 	default:
@@ -368,6 +386,9 @@ int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 	struct inode *inode = filp->f_mapping->host;
 	int err;
 
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
 	err = __generic_file_fsync(filp, start, end, datasync);
 	if (err)
 		return err;

fs/exfat/inode.c

@@ -90,6 +90,9 @@ int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
 	int ret;
 
+	if (unlikely(exfat_forced_shutdown(inode->i_sb)))
+		return -EIO;
+
 	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
 	ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
@@ -346,6 +349,9 @@ static void exfat_readahead(struct readahead_control *rac)
 static int exfat_writepages(struct address_space *mapping,
 		struct writeback_control *wbc)
 {
+	if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
+		return -EIO;
+
 	return mpage_writepages(mapping, wbc, exfat_get_block);
 }
 
@@ -366,6 +372,9 @@ static int exfat_write_begin(struct file *file, struct address_space *mapping,
 {
 	int ret;
 
+	if (unlikely(exfat_forced_shutdown(mapping->host->i_sb)))
+		return -EIO;
+
 	*pagep = NULL;
 	ret = cont_write_begin(file, mapping, pos, len, pagep, fsdata,
 			       exfat_get_block,

fs/exfat/namei.c

@@ -572,6 +572,9 @@ static int exfat_create(struct mnt_idmap *idmap, struct inode *dir,
 	loff_t i_pos;
 	int err;
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return -EIO;
+
 	mutex_lock(&EXFAT_SB(sb)->s_lock);
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
@@ -793,6 +796,9 @@ static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 	struct buffer_head *bh;
 	int num_entries, entry, err = 0;
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return -EIO;
+
 	mutex_lock(&EXFAT_SB(sb)->s_lock);
 	exfat_chain_dup(&cdir, &ei->dir);
 	entry = ei->entry;
@@ -854,6 +860,9 @@ static int exfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 	loff_t i_pos;
 	int err;
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return -EIO;
+
 	mutex_lock(&EXFAT_SB(sb)->s_lock);
 	exfat_set_volume_dirty(sb);
 	err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
@@ -945,6 +954,9 @@ static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 	struct buffer_head *bh;
 	int num_entries, entry, err;
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return -EIO;
+
 	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
 
 	exfat_chain_dup(&cdir, &ei->dir);
@@ -1019,6 +1031,9 @@ static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
 	struct buffer_head *new_bh, *old_bh;
 	int sync = IS_DIRSYNC(inode);
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return -EIO;
+
 	epold = exfat_get_dentry(sb, p_dir, oldentry, &old_bh);
 	if (!epold)
 		return -EIO;

fs/exfat/super.c

@@ -49,6 +49,9 @@ static int exfat_sync_fs(struct super_block *sb, int wait)
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	int err = 0;
 
+	if (unlikely(exfat_forced_shutdown(sb)))
+		return 0;
+
 	if (!wait)
 		return 0;
 
@@ -168,6 +171,41 @@ static int exfat_show_options(struct seq_file *m, struct dentry *root)
 	return 0;
 }
 
+int exfat_force_shutdown(struct super_block *sb, u32 flags)
+{
+	int ret;
+	struct exfat_sb_info *sbi = sb->s_fs_info;
+	struct exfat_mount_options *opts = &sbi->options;
+
+	if (exfat_forced_shutdown(sb))
+		return 0;
+
+	switch (flags) {
+	case EXFAT_GOING_DOWN_DEFAULT:
+	case EXFAT_GOING_DOWN_FULLSYNC:
+		ret = freeze_bdev(sb->s_bdev);
+		if (ret)
+			return ret;
+		thaw_bdev(sb->s_bdev);
+		set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
+		break;
+	case EXFAT_GOING_DOWN_NOSYNC:
+		set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (opts->discard)
+		opts->discard = 0;
+	return 0;
+}
+
+static void exfat_shutdown(struct super_block *sb)
+{
+	exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC);
+}
+
 static struct inode *exfat_alloc_inode(struct super_block *sb)
 {
 	struct exfat_inode_info *ei;
@@ -194,6 +232,7 @@ static const struct super_operations exfat_sops = {
 	.sync_fs	= exfat_sync_fs,
 	.statfs		= exfat_statfs,
 	.show_options	= exfat_show_options,
+	.shutdown	= exfat_shutdown,
 };
 
 enum {

include/uapi/linux/exfat.h

@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2024 Unisoc Technologies Co., Ltd.
+ */
+
+#ifndef _UAPI_LINUX_EXFAT_H
+#define _UAPI_LINUX_EXFAT_H
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/*
+ * exfat-specific ioctl commands
+ */
+
+#define EXFAT_IOC_SHUTDOWN _IOR('X', 125, __u32)
+
+/*
+ * Flags used by EXFAT_IOC_SHUTDOWN
+ */
+
+#define EXFAT_GOING_DOWN_DEFAULT	0x0	/* default with full sync */
+#define EXFAT_GOING_DOWN_FULLSYNC	0x1     /* going down with full sync*/
+#define EXFAT_GOING_DOWN_NOSYNC         0x2     /* going down */
+
+#endif /* _UAPI_LINUX_EXFAT_H */