209 lines
5.3 KiB
C
209 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext2/file.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/file.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext2 fs regular file handling primitives
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*
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* 64-bit file support on 64-bit platforms by Jakub Jelinek
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* (jj@sunsite.ms.mff.cuni.cz)
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*/
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#include <linux/time.h>
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#include <linux/pagemap.h>
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#include <linux/dax.h>
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#include <linux/quotaops.h>
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#include <linux/iomap.h>
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#include <linux/uio.h>
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#include "ext2.h"
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#include "xattr.h"
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#include "acl.h"
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#ifdef CONFIG_FS_DAX
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static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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struct inode *inode = iocb->ki_filp->f_mapping->host;
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ssize_t ret;
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if (!iov_iter_count(to))
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return 0; /* skip atime */
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inode_lock_shared(inode);
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ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
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inode_unlock_shared(inode);
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file_accessed(iocb->ki_filp);
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return ret;
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}
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static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
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{
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struct file *file = iocb->ki_filp;
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struct inode *inode = file->f_mapping->host;
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ssize_t ret;
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inode_lock(inode);
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ret = generic_write_checks(iocb, from);
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if (ret <= 0)
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goto out_unlock;
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ret = file_remove_privs(file);
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if (ret)
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goto out_unlock;
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ret = file_update_time(file);
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if (ret)
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goto out_unlock;
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ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
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if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
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i_size_write(inode, iocb->ki_pos);
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mark_inode_dirty(inode);
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}
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out_unlock:
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inode_unlock(inode);
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if (ret > 0)
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ret = generic_write_sync(iocb, ret);
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return ret;
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}
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/*
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* The lock ordering for ext2 DAX fault paths is:
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*
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* mmap_lock (MM)
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* sb_start_pagefault (vfs, freeze)
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* address_space->invalidate_lock
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* address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
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* ext2_inode_info->truncate_mutex
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*
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* The default page_lock and i_size verification done by non-DAX fault paths
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* is sufficient because ext2 doesn't support hole punching.
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*/
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static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
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{
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struct inode *inode = file_inode(vmf->vma->vm_file);
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vm_fault_t ret;
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bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
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(vmf->vma->vm_flags & VM_SHARED);
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if (write) {
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sb_start_pagefault(inode->i_sb);
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file_update_time(vmf->vma->vm_file);
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}
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filemap_invalidate_lock_shared(inode->i_mapping);
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ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);
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filemap_invalidate_unlock_shared(inode->i_mapping);
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if (write)
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sb_end_pagefault(inode->i_sb);
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return ret;
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}
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static const struct vm_operations_struct ext2_dax_vm_ops = {
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.fault = ext2_dax_fault,
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/*
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* .huge_fault is not supported for DAX because allocation in ext2
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* cannot be reliably aligned to huge page sizes and so pmd faults
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* will always fail and fail back to regular faults.
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*/
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.page_mkwrite = ext2_dax_fault,
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.pfn_mkwrite = ext2_dax_fault,
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};
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static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
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{
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if (!IS_DAX(file_inode(file)))
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return generic_file_mmap(file, vma);
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file_accessed(file);
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vma->vm_ops = &ext2_dax_vm_ops;
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return 0;
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}
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#else
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#define ext2_file_mmap generic_file_mmap
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#endif
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/*
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* Called when filp is released. This happens when all file descriptors
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* for a single struct file are closed. Note that different open() calls
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* for the same file yield different struct file structures.
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*/
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static int ext2_release_file (struct inode * inode, struct file * filp)
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{
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if (filp->f_mode & FMODE_WRITE) {
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mutex_lock(&EXT2_I(inode)->truncate_mutex);
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ext2_discard_reservation(inode);
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mutex_unlock(&EXT2_I(inode)->truncate_mutex);
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}
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return 0;
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}
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int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
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{
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int ret;
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struct super_block *sb = file->f_mapping->host->i_sb;
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ret = generic_file_fsync(file, start, end, datasync);
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if (ret == -EIO)
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/* We don't really know where the IO error happened... */
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ext2_error(sb, __func__,
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"detected IO error when writing metadata buffers");
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return ret;
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}
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static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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#ifdef CONFIG_FS_DAX
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if (IS_DAX(iocb->ki_filp->f_mapping->host))
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return ext2_dax_read_iter(iocb, to);
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#endif
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return generic_file_read_iter(iocb, to);
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}
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static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
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{
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#ifdef CONFIG_FS_DAX
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if (IS_DAX(iocb->ki_filp->f_mapping->host))
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return ext2_dax_write_iter(iocb, from);
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#endif
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return generic_file_write_iter(iocb, from);
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}
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const struct file_operations ext2_file_operations = {
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.llseek = generic_file_llseek,
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.read_iter = ext2_file_read_iter,
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.write_iter = ext2_file_write_iter,
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.unlocked_ioctl = ext2_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = ext2_compat_ioctl,
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#endif
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.mmap = ext2_file_mmap,
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.open = dquot_file_open,
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.release = ext2_release_file,
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.fsync = ext2_fsync,
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.get_unmapped_area = thp_get_unmapped_area,
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.splice_read = generic_file_splice_read,
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.splice_write = iter_file_splice_write,
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};
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const struct inode_operations ext2_file_inode_operations = {
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.listxattr = ext2_listxattr,
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.getattr = ext2_getattr,
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.setattr = ext2_setattr,
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.get_inode_acl = ext2_get_acl,
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.set_acl = ext2_set_acl,
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.fiemap = ext2_fiemap,
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.fileattr_get = ext2_fileattr_get,
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.fileattr_set = ext2_fileattr_set,
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};
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