path: root/fs/gfs2/file.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/compat.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/mount.h>
#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/gfs2_ondisk.h>
#include <linux/falloc.h>
#include <linux/swap.h>
#include <linux/crc32.h>
#include <linux/writeback.h>
#include <linux/uaccess.h>
#include <linux/dlm.h>
#include <linux/dlm_plock.h>
#include <linux/delay.h>
#include <linux/backing-dev.h>
#include <linux/fileattr.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "aops.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "log.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"

/**
 * gfs2_llseek - seek to a location in a file
 * @file: the file
 * @offset: the offset
 * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
 *
 * SEEK_END requires the glock for the file because it references the
 * file's size.
 *
 * Returns: The new offset, or errno
 */

static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_holder i_gh;
	loff_t error;

	switch (whence) {
	case SEEK_END:
		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (!error) {
			error = generic_file_llseek(file, offset, whence);
			gfs2_glock_dq_uninit(&i_gh);
		}
		break;

	case SEEK_DATA:
		error = gfs2_seek_data(file, offset);
		break;

	case SEEK_HOLE:
		error = gfs2_seek_hole(file, offset);
		break;

	case SEEK_CUR:
	case SEEK_SET:
		/*
		 * These don't reference inode->i_size and don't depend on the
		 * block mapping, so we don't need the glock.
		 */
		error = generic_file_llseek(file, offset, whence);
		break;
	default:
		error = -EINVAL;
	}

	return error;
}

/**
 * gfs2_readdir - Iterator for a directory
 * @file: The directory to read from
 * @ctx: What to feed directory entries to
 *
 * Returns: errno
 */

static int gfs2_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *dir = file->f_mapping->host;
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_holder d_gh;
	int error;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
	if (error)
		return error;

	error = gfs2_dir_read(dir, ctx, &file->f_ra);

	gfs2_glock_dq_uninit(&d_gh);

	return error;
}

/*
 * struct fsflag_gfs2flag
 *
 * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories,
 * and to GFS2_DIF_JDATA for non-directories.
 */
static struct {
	u32 fsflag;
	u32 gfsflag;
} fsflag_gfs2flag[] = {
	{FS_SYNC_FL, GFS2_DIF_SYNC},
	{FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE},
	{FS_APPEND_FL, GFS2_DIF_APPENDONLY},
	{FS_NOATIME_FL, GFS2_DIF_NOATIME},
	{FS_INDEX_FL, GFS2_DIF_EXHASH},
	{FS_TOPDIR_FL, GFS2_DIF_TOPDIR},
	{FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
};

static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
{
	int i;
	u32 fsflags = 0;

	if (S_ISDIR(inode->i_mode))
		gfsflags &= ~GFS2_DIF_JDATA;
	else
		gfsflags &= ~GFS2_DIF_INHERIT_JDATA;

	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
		if (gfsflags & fsflag_gfs2flag[i].gfsflag)
			fsflags |= fsflag_gfs2flag[i].fsflag;
	return fsflags;
}

int gfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
{
	struct inode *inode = d_inode(dentry);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int error;
	u32 fsflags;

	if (d_is_special(dentry))
		return -ENOTTY;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
	error = gfs2_glock_nq(&gh);
	if (error)
		goto out_uninit;

	fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);

	fileattr_fill_flags(fa, fsflags);

	gfs2_glock_dq(&gh);
out_uninit:
	gfs2_holder_uninit(&gh);
	return error;
}

void gfs2_set_inode_flags(struct inode *inode)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	unsigned int flags = inode->i_flags;

	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
	if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
		flags |= S_NOSEC;
	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)