1 // SPDX-License-Identifier: GPL-2.0
7  * Laboratoire MASI - Institut Blaise Pascal
18  *  64-bit file support on 64-bit platforms by Jakub Jelinek
32 #include <linux/backing-dev.h>
57 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_should_use_dio()
66 	return IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), dio_align);  in ext4_should_use_dio()
72 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_dio_read_iter()
74 	if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dio_read_iter()
76 			return -EAGAIN;  in ext4_dio_read_iter()
90 		iocb->ki_flags &= ~IOCB_DIRECT;  in ext4_dio_read_iter()
97 	file_accessed(iocb->ki_filp);  in ext4_dio_read_iter()
104 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_dax_read_iter()
107 	if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dax_read_iter()
109 			return -EAGAIN;  in ext4_dax_read_iter()
114 	 * Recheck under inode lock - at this point we are sure it cannot  in ext4_dax_read_iter()
125 	file_accessed(iocb->ki_filp);  in ext4_dax_read_iter()
132 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_file_read_iter()
134 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))  in ext4_file_read_iter()
135 		return -EIO;  in ext4_file_read_iter()
144 	if (iocb->ki_flags & IOCB_DIRECT)  in ext4_file_read_iter()
156 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))  in ext4_file_splice_read()
157 		return -EIO;  in ext4_file_splice_read()
173 	if ((filp->f_mode & FMODE_WRITE) &&  in ext4_release_file()
174 			(atomic_read(&inode->i_writecount) == 1) &&  in ext4_release_file()
175 			!EXT4_I(inode)->i_reserved_data_blocks) {  in ext4_release_file()
176 		down_write(&EXT4_I(inode)->i_data_sem);  in ext4_release_file()
178 		up_write(&EXT4_I(inode)->i_data_sem);  in ext4_release_file()
180 	if (is_dx(inode) && filp->private_data)  in ext4_release_file()
181 		ext4_htree_free_dir_info(filp->private_data);  in ext4_release_file()
187  * This tests whether the IO in question is block-aligned or not.
188  * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
198 	struct super_block *sb = inode->i_sb;  in ext4_unaligned_io()
199 	unsigned long blockmask = sb->s_blocksize - 1;  in ext4_unaligned_io()
211 	    offset + len > EXT4_I(inode)->i_disksize)  in ext4_extending_io()
221 	unsigned int blkbits = inode->i_blkbits;  in ext4_overwrite_io()
246 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_generic_write_checks()
250 		return -EPERM;  in ext4_generic_write_checks()
257 	 * If we have encountered a bitmap-format file, the size limit  in ext4_generic_write_checks()
258 	 * is smaller than s_maxbytes, which is for extent-mapped files.  in ext4_generic_write_checks()
261 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);  in ext4_generic_write_checks()
263 		if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)  in ext4_generic_write_checks()
264 			return -EFBIG;  in ext4_generic_write_checks()
265 		iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);  in ext4_generic_write_checks()
279 	ret = file_modified(iocb->ki_filp);  in ext4_write_checks()
289 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_buffered_write_iter()
291 	if (iocb->ki_flags & IOCB_NOWAIT)  in ext4_buffered_write_iter()
292 		return -EOPNOTSUPP;  in ext4_buffered_write_iter()
313 	lockdep_assert_held_write(&inode->i_rwsem);  in ext4_handle_inode_extension()
326 	if ((written == count) && inode->i_nlink)  in ext4_handle_inode_extension()
339 	lockdep_assert_held_write(&inode->i_rwsem);  in ext4_inode_extension_cleanup()
345 		 * remove the inode from the in-memory linked list.  in ext4_inode_extension_cleanup()
347 		if (inode->i_nlink)  in ext4_inode_extension_cleanup()
357 	if (!list_empty(&EXT4_I(inode)->i_orphan) && inode->i_nlink) {  in ext4_inode_extension_cleanup()
377 	loff_t pos = iocb->ki_pos;  in ext4_dio_write_end_io()
378 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_dio_write_end_io()
385 	 * Note that EXT4_I(inode)->i_disksize can get extended up to  in ext4_dio_write_end_io()
386 	 * inode->i_size while the I/O was running due to writeback of delalloc  in ext4_dio_write_end_io()
393 	if (pos + size <= READ_ONCE(EXT4_I(inode)->i_disksize) &&  in ext4_dio_write_end_io()
406  * condition requires an exclusive inode lock. If yes, then we restart the
407  * whole operation by releasing the shared lock and acquiring exclusive lock.
409  * - For unaligned_io we never take shared lock as it may cause data corruption
412  * - For extending writes case we don't take the shared lock, since it requires
413  *   updating inode i_disksize and/or orphan handling with exclusive lock.
415  * - shared locking will only be true mostly with overwrites, including
418  *   also release exclusive i_rwsem lock.
420  * - Otherwise we will switch to exclusive i_rwsem lock.
426 	struct file *file = iocb->ki_filp;  in ext4_dio_write_checks()
438 	offset = iocb->ki_pos;  in ext4_dio_write_checks()
446 	 * Determine whether we need to upgrade to an exclusive lock. This is  in ext4_dio_write_checks()
448 	 * I/O, any form of non-overwrite I/O, and unaligned I/O to unwritten  in ext4_dio_write_checks()
459 		if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dio_write_checks()
460 			ret = -EAGAIN;  in ext4_dio_write_checks()
472 	 * behavior already. The inode lock is already held exclusive if the  in ext4_dio_write_checks()
473 	 * write is non-overwrite or extending, so drain all outstanding dio and  in ext4_dio_write_checks()
477 		if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dio_write_checks()
478 			ret = -EAGAIN;  in ext4_dio_write_checks()
503 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_dio_write_iter()
504 	loff_t offset = iocb->ki_pos;  in ext4_dio_write_iter()
519 	if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dio_write_iter()
522 				return -EAGAIN;  in ext4_dio_write_iter()
525 				return -EAGAIN;  in ext4_dio_write_iter()
557 	offset = iocb->ki_pos;  in ext4_dio_write_iter()
577 	if (ret == -ENOTBLK)  in ext4_dio_write_iter()
586 		WARN_ON_ONCE(ret == -EIOCBQUEUED);  in ext4_dio_write_iter()
601 		 * There is no support for atomic writes on buffered-io yet,  in ext4_dio_write_iter()
602 		 * we should never fallback to buffered-io for DIO atomic  in ext4_dio_write_iter()
605 		WARN_ON_ONCE(iocb->ki_flags & IOCB_ATOMIC);  in ext4_dio_write_iter()
607 		offset = iocb->ki_pos;  in ext4_dio_write_iter()
620 		endbyte = offset + err - 1;  in ext4_dio_write_iter()
621 		err = filemap_write_and_wait_range(iocb->ki_filp->f_mapping,  in ext4_dio_write_iter()
624 			invalidate_mapping_pages(iocb->ki_filp->f_mapping,  in ext4_dio_write_iter()
641 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_dax_write_iter()
643 	if (iocb->ki_flags & IOCB_NOWAIT) {  in ext4_dax_write_iter()
645 			return -EAGAIN;  in ext4_dax_write_iter()
654 	offset = iocb->ki_pos;  in ext4_dax_write_iter()
657 	if (offset + count > EXT4_I(inode)->i_disksize) {  in ext4_dax_write_iter()
691 	struct inode *inode = file_inode(iocb->ki_filp);  in ext4_file_write_iter()
693 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))  in ext4_file_write_iter()
694 		return -EIO;  in ext4_file_write_iter()
701 	if (iocb->ki_flags & IOCB_ATOMIC) {  in ext4_file_write_iter()
705 		if (len < EXT4_SB(inode->i_sb)->s_awu_min ||  in ext4_file_write_iter()
706 		    len > EXT4_SB(inode->i_sb)->s_awu_max)  in ext4_file_write_iter()
707 			return -EINVAL;  in ext4_file_write_iter()
714 	if (iocb->ki_flags & IOCB_DIRECT)  in ext4_file_write_iter()
727 	struct inode *inode = file_inode(vmf->vma->vm_file);  in ext4_dax_huge_fault()
728 	struct super_block *sb = inode->i_sb;  in ext4_dax_huge_fault()
734 	 * read-only.  in ext4_dax_huge_fault()
736 	 * We check for VM_SHARED rather than vmf->cow_page since the latter is  in ext4_dax_huge_fault()
741 	bool write = (vmf->flags & FAULT_FLAG_WRITE) &&  in ext4_dax_huge_fault()
742 		(vmf->vma->vm_flags & VM_SHARED);  in ext4_dax_huge_fault()
743 	struct address_space *mapping = vmf->vma->vm_file->f_mapping;  in ext4_dax_huge_fault()
748 		file_update_time(vmf->vma->vm_file);  in ext4_dax_huge_fault()
765 		if ((result & VM_FAULT_ERROR) && error == -ENOSPC &&  in ext4_dax_huge_fault()
803 	struct inode *inode = file->f_mapping->host;  in ext4_file_mmap()
804 	struct dax_device *dax_dev = EXT4_SB(inode->i_sb)->s_daxdev;  in ext4_file_mmap()
806 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))  in ext4_file_mmap()
807 		return -EIO;  in ext4_file_mmap()
810 	 * We don't support synchronous mappings for non-DAX files and  in ext4_file_mmap()
814 		return -EOPNOTSUPP;  in ext4_file_mmap()
818 		vma->vm_ops = &ext4_dax_vm_ops;  in ext4_file_mmap()
821 		vma->vm_ops = &ext4_file_vm_ops;  in ext4_file_mmap()
850 	path.dentry = mnt->mnt_root;  in ext4_sample_last_mounted()
860 	BUFFER_TRACE(sbi->s_sbh, "get_write_access");  in ext4_sample_last_mounted()
861 	err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,  in ext4_sample_last_mounted()
865 	lock_buffer(sbi->s_sbh);  in ext4_sample_last_mounted()
866 	strtomem_pad(sbi->s_es->s_last_mounted, cp, 0);  in ext4_sample_last_mounted()
868 	unlock_buffer(sbi->s_sbh);  in ext4_sample_last_mounted()
869 	ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);  in ext4_sample_last_mounted()
881 	if (unlikely(ext4_forced_shutdown(inode->i_sb)))  in ext4_file_open()
882 		return -EIO;  in ext4_file_open()
884 	ret = ext4_sample_last_mounted(inode->i_sb, filp->f_path.mnt);  in ext4_file_open()
900 	if (filp->f_mode & FMODE_WRITE) {  in ext4_file_open()
907 		filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;  in ext4_file_open()
909 	filp->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT;  in ext4_file_open()
914  * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
920 	struct inode *inode = file->f_mapping->host;  in ext4_llseek()
924 		maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;  in ext4_llseek()
926 		maxbytes = inode->i_sb->s_maxbytes;  in ext4_llseek()