ext4: add shutdown bit and check for it

Add a shutdown bit that will cause ext4 processing to fail immediately
with EIO.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4.h

@@ -1836,6 +1836,12 @@ static inline bool ext4_has_incompat_features(struct super_block *sb)
  * Superblock flags
  */
 #define EXT4_FLAGS_RESIZING	0
+#define EXT4_FLAGS_SHUTDOWN	1
+
+static inline int ext4_forced_shutdown(struct ext4_sb_info *sbi)
+{
+	return test_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags);
+}
 
 
 /*

fs/ext4/ext4_jbd2.c

@@ -43,6 +43,10 @@ static int ext4_journal_check_start(struct super_block *sb)
 	journal_t *journal;
 
 	might_sleep();
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return -EIO;
+
 	if (sb->s_flags & MS_RDONLY)
 		return -EROFS;
 	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
@@ -161,6 +165,13 @@ int __ext4_journal_get_write_access(const char *where, unsigned int line,
 	might_sleep();
 
 	if (ext4_handle_valid(handle)) {
+		struct super_block *sb;
+
+		sb = handle->h_transaction->t_journal->j_private;
+		if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) {
+			jbd2_journal_abort_handle(handle);
+			return -EIO;
+		}
 		err = jbd2_journal_get_write_access(handle, bh);
 		if (err)
 			ext4_journal_abort_handle(where, line, __func__, bh,

fs/ext4/file.c

@@ -57,6 +57,9 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
 static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(file_inode(iocb->ki_filp)->i_sb))))
+		return -EIO;
+
 	if (!iov_iter_count(to))
 		return 0; /* skip atime */
 
@@ -213,6 +216,9 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	int overwrite = 0;
 	ssize_t ret;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 #ifdef CONFIG_FS_DAX
 	if (IS_DAX(inode))
 		return ext4_dax_write_iter(iocb, from);
@@ -348,6 +354,9 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct inode *inode = file->f_mapping->host;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (ext4_encrypted_inode(inode)) {
 		int err = fscrypt_get_encryption_info(inode);
 		if (err)
@@ -375,6 +384,9 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
 	char buf[64], *cp;
 	int ret;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
 		     !(sb->s_flags & MS_RDONLY))) {
 		sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;

fs/ext4/fsync.c

@@ -100,6 +100,9 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	tid_t commit_tid;
 	bool needs_barrier = false;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	J_ASSERT(ext4_journal_current_handle() == NULL);
 
 	trace_ext4_sync_file_enter(file, datasync);

fs/ext4/ialloc.c

@@ -764,6 +764,9 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 	if (!dir || !dir->i_nlink)
 		return ERR_PTR(-EPERM);
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
+		return ERR_PTR(-EIO);
+
 	if ((ext4_encrypted_inode(dir) ||
 	     DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&
 	    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {

fs/ext4/inline.c

@@ -215,6 +215,9 @@ static void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc,
 	struct ext4_inode *raw_inode;
 	int cp_len = 0;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return;
+
 	BUG_ON(!EXT4_I(inode)->i_inline_off);
 	BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);
 

fs/ext4/inode.c

@@ -1189,6 +1189,9 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
 	pgoff_t index;
 	unsigned from, to;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	trace_ext4_write_begin(inode, pos, len, flags);
 	/*
 	 * Reserve one block more for addition to orphan list in case
@@ -2047,6 +2050,12 @@ static int ext4_writepage(struct page *page,
 	struct ext4_io_submit io_submit;
 	bool keep_towrite = false;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) {
+		ext4_invalidatepage(page, 0, PAGE_SIZE);
+		unlock_page(page);
+		return -EIO;
+	}
+
 	trace_ext4_writepage(page);
 	size = i_size_read(inode);
 	if (page->index == size >> PAGE_SHIFT)
@@ -2422,7 +2431,8 @@ static int mpage_map_and_submit_extent(handle_t *handle,
 		if (err < 0) {
 			struct super_block *sb = inode->i_sb;
 
-			if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+			if (ext4_forced_shutdown(EXT4_SB(sb)) ||
+			    EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
 				goto invalidate_dirty_pages;
 			/*
 			 * Let the uper layers retry transient errors.
@@ -2644,6 +2654,9 @@ static int ext4_writepages(struct address_space *mapping,
 	struct blk_plug plug;
 	bool give_up_on_write = false;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	percpu_down_read(&sbi->s_journal_flag_rwsem);
 	trace_ext4_writepages(inode, wbc);
 
@@ -2680,7 +2693,8 @@ static int ext4_writepages(struct address_space *mapping,
 	 * *never* be called, so if that ever happens, we would want
 	 * the stack trace.
 	 */
-	if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(mapping->host->i_sb)) ||
+		     sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
 		ret = -EROFS;
 		goto out_writepages;
 	}
@@ -2905,6 +2919,9 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
 	struct inode *inode = mapping->host;
 	handle_t *handle;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	index = pos >> PAGE_SHIFT;
 
 	if (ext4_nonda_switch(inode->i_sb) ||
@@ -5212,6 +5229,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 	int orphan = 0;
 	const unsigned int ia_valid = attr->ia_valid;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	error = setattr_prepare(dentry, attr);
 	if (error)
 		return error;
@@ -5498,6 +5518,9 @@ int ext4_mark_iloc_dirty(handle_t *handle,
 {
 	int err = 0;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (IS_I_VERSION(inode))
 		inode_inc_iversion(inode);
 
@@ -5521,6 +5544,9 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 {
 	int err;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	err = ext4_get_inode_loc(inode, iloc);
 	if (!err) {
 		BUFFER_TRACE(iloc->bh, "get_write_access");

fs/ext4/namei.c

@@ -2939,6 +2939,9 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 	struct ext4_dir_entry_2 *de;
 	handle_t *handle = NULL;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
+		return -EIO;
+
 	/* Initialize quotas before so that eventual writes go in
 	 * separate transaction */
 	retval = dquot_initialize(dir);
@@ -3012,6 +3015,9 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 	struct ext4_dir_entry_2 *de;
 	handle_t *handle = NULL;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
+		return -EIO;
+
 	trace_ext4_unlink_enter(dir, dentry);
 	/* Initialize quotas before so that eventual writes go
 	 * in separate transaction */
@@ -3082,6 +3088,9 @@ static int ext4_symlink(struct inode *dir,
 	struct fscrypt_str disk_link;
 	struct fscrypt_symlink_data *sd = NULL;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
+		return -EIO;
+
 	disk_link.len = len + 1;
 	disk_link.name = (char *) symname;
 
@@ -3874,6 +3883,9 @@ static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry,
 			struct inode *new_dir, struct dentry *new_dentry,
 			unsigned int flags)
 {
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
+		return -EIO;
+
 	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
 		return -EINVAL;
 

fs/ext4/page-io.c

@@ -158,7 +158,7 @@ static int ext4_end_io(ext4_io_end_t *io)
 
 	io->handle = NULL;	/* Following call will use up the handle */
 	ret = ext4_convert_unwritten_extents(handle, inode, offset, size);
-	if (ret < 0) {
+	if (ret < 0 && !ext4_forced_shutdown(EXT4_SB(inode->i_sb))) {
 		ext4_msg(inode->i_sb, KERN_EMERG,
 			 "failed to convert unwritten extents to written "
 			 "extents -- potential data loss!  "

fs/ext4/super.c

@@ -438,6 +438,9 @@ void __ext4_error(struct super_block *sb, const char *function,
 	struct va_format vaf;
 	va_list args;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return;
+
 	if (ext4_error_ratelimit(sb)) {
 		va_start(args, fmt);
 		vaf.fmt = fmt;
@@ -459,6 +462,9 @@ void __ext4_error_inode(struct inode *inode, const char *function,
 	struct va_format vaf;
 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return;
+
 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 	es->s_last_error_block = cpu_to_le64(block);
 	if (ext4_error_ratelimit(inode->i_sb)) {
@@ -491,6 +497,9 @@ void __ext4_error_file(struct file *file, const char *function,
 	struct inode *inode = file_inode(file);
 	char pathname[80], *path;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return;
+
 	es = EXT4_SB(inode->i_sb)->s_es;
 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 	if (ext4_error_ratelimit(inode->i_sb)) {
@@ -567,6 +576,9 @@ void __ext4_std_error(struct super_block *sb, const char *function,
 	char nbuf[16];
 	const char *errstr;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return;
+
 	/* Special case: if the error is EROFS, and we're not already
 	 * inside a transaction, then there's really no point in logging
 	 * an error. */
@@ -600,6 +612,9 @@ void __ext4_abort(struct super_block *sb, const char *function,
 	struct va_format vaf;
 	va_list args;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return;
+
 	save_error_info(sb, function, line);
 	va_start(args, fmt);
 	vaf.fmt = fmt;
@@ -695,6 +710,9 @@ __acquires(bitlock)
 	va_list args;
 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return;
+
 	es->s_last_error_ino = cpu_to_le32(ino);
 	es->s_last_error_block = cpu_to_le64(block);
 	__save_error_info(sb, function, line);
@@ -4717,6 +4735,9 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 	bool needs_barrier = false;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
+		return 0;
+
 	trace_ext4_sync_fs(sb, wait);
 	flush_workqueue(sbi->rsv_conversion_wq);
 	/*

fs/ext4/xattr.c

@@ -411,6 +411,9 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name,
 {
 	int error;
 
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
 	if (strlen(name) > 255)
 		return -ERANGE;