file.c 26.2 KB
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/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
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 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
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 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
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 * of the GNU General Public License version 2.
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 */

#include <linux/slab.h>
#include <linux/spinlock.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>
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#include <linux/mount.h>
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#include <linux/fs.h>
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#include <linux/gfs2_ondisk.h>
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#include <linux/ext2_fs.h>
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#include <linux/falloc.h>
#include <linux/swap.h>
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#include <linux/crc32.h>
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#include <linux/writeback.h>
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#include <asm/uaccess.h>
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#include <linux/dlm.h>
#include <linux/dlm_plock.h>
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#include "gfs2.h"
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#include "incore.h"
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#include "bmap.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"
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#include "util.h"
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/**
 * gfs2_llseek - seek to a location in a file
 * @file: the file
 * @offset: the offset
 * @origin: 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 origin)
{
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	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
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	struct gfs2_holder i_gh;
	loff_t error;

	if (origin == 2) {
		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (!error) {
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			error = generic_file_llseek_unlocked(file, offset, origin);
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			gfs2_glock_dq_uninit(&i_gh);
		}
	} else
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		error = generic_file_llseek_unlocked(file, offset, origin);
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	return error;
}

/**
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 * gfs2_readdir - Read directory entries from a directory
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 * @file: The directory to read from
 * @dirent: Buffer for dirents
 * @filldir: Function used to do the copying
 *
 * Returns: errno
 */

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static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
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{
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	struct inode *dir = file->f_mapping->host;
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	struct gfs2_inode *dip = GFS2_I(dir);
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	struct gfs2_holder d_gh;
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	u64 offset = file->f_pos;
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	int error;

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	gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
	error = gfs2_glock_nq(&d_gh);
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	if (error) {
		gfs2_holder_uninit(&d_gh);
		return error;
	}

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	error = gfs2_dir_read(dir, &offset, dirent, filldir);
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	gfs2_glock_dq_uninit(&d_gh);

	file->f_pos = offset;

	return error;
}

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/**
 * fsflags_cvt
 * @table: A table of 32 u32 flags
 * @val: a 32 bit value to convert
 *
 * This function can be used to convert between fsflags values and
 * GFS2's own flags values.
 *
 * Returns: the converted flags
 */
static u32 fsflags_cvt(const u32 *table, u32 val)
{
	u32 res = 0;
	while(val) {
		if (val & 1)
			res |= *table;
		table++;
		val >>= 1;
	}
	return res;
}
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static const u32 fsflags_to_gfs2[32] = {
	[3] = GFS2_DIF_SYNC,
	[4] = GFS2_DIF_IMMUTABLE,
	[5] = GFS2_DIF_APPENDONLY,
	[7] = GFS2_DIF_NOATIME,
	[12] = GFS2_DIF_EXHASH,
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	[14] = GFS2_DIF_INHERIT_JDATA,
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};

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static const u32 gfs2_to_fsflags[32] = {
	[gfs2fl_Sync] = FS_SYNC_FL,
	[gfs2fl_Immutable] = FS_IMMUTABLE_FL,
	[gfs2fl_AppendOnly] = FS_APPEND_FL,
	[gfs2fl_NoAtime] = FS_NOATIME_FL,
	[gfs2fl_ExHash] = FS_INDEX_FL,
	[gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
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};
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static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
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{
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	struct inode *inode = filp->f_path.dentry->d_inode;
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	struct gfs2_inode *ip = GFS2_I(inode);
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	struct gfs2_holder gh;
	int error;
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	u32 fsflags;
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	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
	error = gfs2_glock_nq(&gh);
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	if (error)
		return error;
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	fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
	if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
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		fsflags |= FS_JOURNAL_DATA_FL;
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	if (put_user(fsflags, ptr))
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		error = -EFAULT;

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

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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);
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	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
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		flags |= S_IMMUTABLE;
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	if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
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		flags |= S_APPEND;
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	if (ip->i_diskflags & GFS2_DIF_NOATIME)
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		flags |= S_NOATIME;
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	if (ip->i_diskflags & GFS2_DIF_SYNC)
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		flags |= S_SYNC;
	inode->i_flags = flags;
}

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/* Flags that can be set by user space */
#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
			     GFS2_DIF_IMMUTABLE|		\
			     GFS2_DIF_APPENDONLY|		\
			     GFS2_DIF_NOATIME|			\
			     GFS2_DIF_SYNC|			\
			     GFS2_DIF_SYSTEM|			\
			     GFS2_DIF_INHERIT_JDATA)

/**
 * gfs2_set_flags - set flags on an inode
 * @inode: The inode
 * @flags: The flags to set
 * @mask: Indicates which flags are valid
 *
 */
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static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
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{
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	struct inode *inode = filp->f_path.dentry->d_inode;
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	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
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	struct buffer_head *bh;
	struct gfs2_holder gh;
	int error;
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	u32 new_flags, flags;
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	error = mnt_want_write(filp->f_path.mnt);
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	if (error)
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		return error;

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	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	if (error)
		goto out_drop_write;

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	error = -EACCES;
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	if (!inode_owner_or_capable(inode))
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		goto out;

	error = 0;
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	flags = ip->i_diskflags;
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	new_flags = (flags & ~mask) | (reqflags & mask);
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	if ((new_flags ^ flags) == 0)
		goto out;

	error = -EINVAL;
	if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
		goto out;

	error = -EPERM;
	if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
		goto out;
	if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
		goto out;
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	if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
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	    !capable(CAP_LINUX_IMMUTABLE))
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		goto out;
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	if (!IS_IMMUTABLE(inode)) {
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		error = gfs2_permission(inode, MAY_WRITE);
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		if (error)
			goto out;
	}
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	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
		if (flags & GFS2_DIF_JDATA)
			gfs2_log_flush(sdp, ip->i_gl);
		error = filemap_fdatawrite(inode->i_mapping);
		if (error)
			goto out;
		error = filemap_fdatawait(inode->i_mapping);
		if (error)
			goto out;
	}
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	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
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	if (error)
		goto out;
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	error = gfs2_meta_inode_buffer(ip, &bh);
	if (error)
		goto out_trans_end;
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	gfs2_trans_add_bh(ip->i_gl, bh, 1);
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	ip->i_diskflags = new_flags;
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	gfs2_dinode_out(ip, bh->b_data);
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	brelse(bh);
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	gfs2_set_inode_flags(inode);
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	gfs2_set_aops(inode);
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out_trans_end:
	gfs2_trans_end(sdp);
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out:
	gfs2_glock_dq_uninit(&gh);
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out_drop_write:
	mnt_drop_write(filp->f_path.mnt);
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	return error;
}

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static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
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{
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	struct inode *inode = filp->f_path.dentry->d_inode;
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	u32 fsflags, gfsflags;
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	if (get_user(fsflags, ptr))
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		return -EFAULT;
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	gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
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	if (!S_ISDIR(inode->i_mode)) {
		if (gfsflags & GFS2_DIF_INHERIT_JDATA)
			gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
		return do_gfs2_set_flags(filp, gfsflags, ~0);
	}
	return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
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}

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static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
	switch(cmd) {
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	case FS_IOC_GETFLAGS:
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		return gfs2_get_flags(filp, (u32 __user *)arg);
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	case FS_IOC_SETFLAGS:
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		return gfs2_set_flags(filp, (u32 __user *)arg);
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	}
	return -ENOTTY;
}

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/**
 * gfs2_allocate_page_backing - Use bmap to allocate blocks
 * @page: The (locked) page to allocate backing for
 *
 * We try to allocate all the blocks required for the page in
 * one go. This might fail for various reasons, so we keep
 * trying until all the blocks to back this page are allocated.
 * If some of the blocks are already allocated, thats ok too.
 */

static int gfs2_allocate_page_backing(struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct buffer_head bh;
	unsigned long size = PAGE_CACHE_SIZE;
	u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);

	do {
		bh.b_state = 0;
		bh.b_size = size;
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		gfs2_block_map(inode, lblock, &bh, 1);
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		if (!buffer_mapped(&bh))
			return -EIO;
		size -= bh.b_size;
		lblock += (bh.b_size >> inode->i_blkbits);
	} while(size > 0);
	return 0;
}

/**
 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
 * @vma: The virtual memory area
 * @page: The page which is about to become writable
 *
 * When the page becomes writable, we need to ensure that we have
 * blocks allocated on disk to back that page.
 */

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static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
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{
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	struct page *page = vmf->page;
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	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	unsigned long last_index;
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	u64 pos = page->index << PAGE_CACHE_SHIFT;
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	unsigned int data_blocks, ind_blocks, rblocks;
	struct gfs2_holder gh;
	struct gfs2_alloc *al;
	int ret;

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	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	ret = gfs2_glock_nq(&gh);
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	if (ret)
		goto out;

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	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
	set_bit(GIF_SW_PAGED, &ip->i_flags);

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	if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE))
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		goto out_unlock;
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	ret = -ENOMEM;
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	al = gfs2_alloc_get(ip);
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	if (al == NULL)
		goto out_unlock;

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	ret = gfs2_quota_lock_check(ip);
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	if (ret)
		goto out_alloc_put;
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	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
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	al->al_requested = data_blocks + ind_blocks;
	ret = gfs2_inplace_reserve(ip);
	if (ret)
		goto out_quota_unlock;

	rblocks = RES_DINODE + ind_blocks;
	if (gfs2_is_jdata(ip))
		rblocks += data_blocks ? data_blocks : 1;
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	if (ind_blocks || data_blocks) {
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		rblocks += RES_STATFS + RES_QUOTA;
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		rblocks += gfs2_rg_blocks(al);
	}
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	ret = gfs2_trans_begin(sdp, rblocks, 0);
	if (ret)
		goto out_trans_fail;

	lock_page(page);
	ret = -EINVAL;
	last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
	if (page->index > last_index)
		goto out_unlock_page;
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	ret = 0;
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	if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
		goto out_unlock_page;
	if (gfs2_is_stuffed(ip)) {
		ret = gfs2_unstuff_dinode(ip, page);
		if (ret)
			goto out_unlock_page;
	}
	ret = gfs2_allocate_page_backing(page);

out_unlock_page:
	unlock_page(page);
	gfs2_trans_end(sdp);
out_trans_fail:
	gfs2_inplace_release(ip);
out_quota_unlock:
	gfs2_quota_unlock(ip);
out_alloc_put:
	gfs2_alloc_put(ip);
out_unlock:
	gfs2_glock_dq(&gh);
out:
	gfs2_holder_uninit(&gh);
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	if (ret == -ENOMEM)
		ret = VM_FAULT_OOM;
	else if (ret)
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		ret = VM_FAULT_SIGBUS;
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	return ret;
}

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static const struct vm_operations_struct gfs2_vm_ops = {
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	.fault = filemap_fault,
	.page_mkwrite = gfs2_page_mkwrite,
};

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/**
 * gfs2_mmap -
 * @file: The file to map
 * @vma: The VMA which described the mapping
 *
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 * There is no need to get a lock here unless we should be updating
 * atime. We ignore any locking errors since the only consequence is
 * a missed atime update (which will just be deferred until later).
 *
 * Returns: 0
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 */

static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
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	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
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	if (!(file->f_flags & O_NOATIME) &&
	    !IS_NOATIME(&ip->i_inode)) {
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		struct gfs2_holder i_gh;
		int error;
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		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
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		error = gfs2_glock_nq(&i_gh);
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		if (error == 0) {
			file_accessed(file);
			gfs2_glock_dq(&i_gh);
		}
		gfs2_holder_uninit(&i_gh);
		if (error)
			return error;
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	}
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	vma->vm_ops = &gfs2_vm_ops;
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	vma->vm_flags |= VM_CAN_NONLINEAR;
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	return 0;
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}

/**
 * gfs2_open - open a file
 * @inode: the inode to open
 * @file: the struct file for this opening
 *
 * Returns: errno
 */

static int gfs2_open(struct inode *inode, struct file *file)
{
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	struct gfs2_inode *ip = GFS2_I(inode);
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	struct gfs2_holder i_gh;
	struct gfs2_file *fp;
	int error;

	fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
	if (!fp)
		return -ENOMEM;

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	mutex_init(&fp->f_fl_mutex);
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	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
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	file->private_data = fp;
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	if (S_ISREG(ip->i_inode.i_mode)) {
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		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (error)
			goto fail;

		if (!(file->f_flags & O_LARGEFILE) &&
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		    i_size_read(inode) > MAX_NON_LFS) {
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			error = -EOVERFLOW;
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			goto fail_gunlock;
		}

		gfs2_glock_dq_uninit(&i_gh);
	}

	return 0;

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fail_gunlock:
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	gfs2_glock_dq_uninit(&i_gh);
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fail:
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	file->private_data = NULL;
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	kfree(fp);
	return error;
}

/**
 * gfs2_close - called to close a struct file
 * @inode: the inode the struct file belongs to
 * @file: the struct file being closed
 *
 * Returns: errno
 */

static int gfs2_close(struct inode *inode, struct file *file)
{
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	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
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	struct gfs2_file *fp;

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	fp = file->private_data;
	file->private_data = NULL;
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	if (gfs2_assert_warn(sdp, fp))
		return -EIO;

	kfree(fp);

	return 0;
}

/**
 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 * @file: the file that points to the dentry (we ignore this)
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 * @datasync: set if we can ignore timestamp changes
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 *
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 * The VFS will flush data for us. We only need to worry
 * about metadata here.
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 *
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 * Returns: errno
 */

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static int gfs2_fsync(struct file *file, int datasync)
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{
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	struct inode *inode = file->f_mapping->host;
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	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
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	struct gfs2_inode *ip = GFS2_I(inode);
	int ret;
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	if (datasync)
		sync_state &= ~I_DIRTY_SYNC;
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	if (sync_state) {
		ret = sync_inode_metadata(inode, 1);
		if (ret)
			return ret;
		gfs2_ail_flush(ip->i_gl);
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	}

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	return 0;
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}

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/**
 * gfs2_file_aio_write - Perform a write to a file
 * @iocb: The io context
 * @iov: The data to write
 * @nr_segs: Number of @iov segments
 * @pos: The file position
 *
 * We have to do a lock/unlock here to refresh the inode size for
 * O_APPEND writes, otherwise we can land up writing at the wrong
 * offset. There is still a race, but provided the app is using its
 * own file locking, this will make O_APPEND work as expected.
 *
 */

static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
				   unsigned long nr_segs, loff_t pos)
{
	struct file *file = iocb->ki_filp;

	if (file->f_flags & O_APPEND) {
		struct dentry *dentry = file->f_dentry;
		struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
		struct gfs2_holder gh;
		int ret;

		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
		if (ret)
			return ret;
		gfs2_glock_dq_uninit(&gh);
	}

	return generic_file_aio_write(iocb, iov, nr_segs, pos);
}

610 611
static int empty_write_end(struct page *page, unsigned from,
			   unsigned to, int mode)
612
{
613 614 615 616 617
	struct inode *inode = page->mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct buffer_head *bh;
	unsigned offset, blksize = 1 << inode->i_blkbits;
	pgoff_t end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
618

619
	zero_user(page, from, to-from);
620 621
	mark_page_accessed(page);

622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641
	if (page->index < end_index || !(mode & FALLOC_FL_KEEP_SIZE)) {
		if (!gfs2_is_writeback(ip))
			gfs2_page_add_databufs(ip, page, from, to);

		block_commit_write(page, from, to);
		return 0;
	}

	offset = 0;
	bh = page_buffers(page);
	while (offset < to) {
		if (offset >= from) {
			set_buffer_uptodate(bh);
			mark_buffer_dirty(bh);
			clear_buffer_new(bh);
			write_dirty_buffer(bh, WRITE);
		}
		offset += blksize;
		bh = bh->b_this_page;
	}
642

643 644 645 646 647 648 649 650 651 652 653 654
	offset = 0;
	bh = page_buffers(page);
	while (offset < to) {
		if (offset >= from) {
			wait_on_buffer(bh);
			if (!buffer_uptodate(bh))
				return -EIO;
		}
		offset += blksize;
		bh = bh->b_this_page;
	}
	return 0;
655 656
}

657
static int needs_empty_write(sector_t block, struct inode *inode)
658 659
{
	int error;
660
	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
661

662 663 664 665 666 667
	bh_map.b_size = 1 << inode->i_blkbits;
	error = gfs2_block_map(inode, block, &bh_map, 0);
	if (unlikely(error))
		return error;
	return !buffer_mapped(&bh_map);
}
668

669 670
static int write_empty_blocks(struct page *page, unsigned from, unsigned to,
			      int mode)
671 672 673 674 675
{
	struct inode *inode = page->mapping->host;
	unsigned start, end, next, blksize;
	sector_t block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
	int ret;
676

677
	blksize = 1 << inode->i_blkbits;
678 679
	next = end = 0;
	while (next < from) {
680 681
		next += blksize;
		block++;
682 683 684
	}
	start = next;
	do {
685 686 687 688 689
		next += blksize;
		ret = needs_empty_write(block, inode);
		if (unlikely(ret < 0))
			return ret;
		if (ret == 0) {
690
			if (end) {
691 692 693 694
				ret = __block_write_begin(page, start, end - start,
							  gfs2_block_map);
				if (unlikely(ret))
					return ret;
695 696 697
				ret = empty_write_end(page, start, end, mode);
				if (unlikely(ret))
					return ret;
698 699 700 701 702 703
				end = 0;
			}
			start = next;
		}
		else
			end = next;
704
		block++;
705 706 707
	} while (next < to);

	if (end) {
708 709 710
		ret = __block_write_begin(page, start, end - start, gfs2_block_map);
		if (unlikely(ret))
			return ret;
711 712 713
		ret = empty_write_end(page, start, end, mode);
		if (unlikely(ret))
			return ret;
714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
	}

	return 0;
}

static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
			   int mode)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct buffer_head *dibh;
	int error;
	u64 start = offset >> PAGE_CACHE_SHIFT;
	unsigned int start_offset = offset & ~PAGE_CACHE_MASK;
	u64 end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
	pgoff_t curr;
	struct page *page;
	unsigned int end_offset = (offset + len) & ~PAGE_CACHE_MASK;
	unsigned int from, to;

	if (!end_offset)
		end_offset = PAGE_CACHE_SIZE;

	error = gfs2_meta_inode_buffer(ip, &dibh);
	if (unlikely(error))
		goto out;

	gfs2_trans_add_bh(ip->i_gl, dibh, 1);

	if (gfs2_is_stuffed(ip)) {
		error = gfs2_unstuff_dinode(ip, NULL);
		if (unlikely(error))
			goto out;
	}

	curr = start;
	offset = start << PAGE_CACHE_SHIFT;
	from = start_offset;
	to = PAGE_CACHE_SIZE;
	while (curr <= end) {
		page = grab_cache_page_write_begin(inode->i_mapping, curr,
						   AOP_FLAG_NOFS);
		if (unlikely(!page)) {
			error = -ENOMEM;
			goto out;
		}

		if (curr == end)
			to = end_offset;
762
		error = write_empty_blocks(page, from, to, mode);
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818
		if (!error && offset + to > inode->i_size &&
		    !(mode & FALLOC_FL_KEEP_SIZE)) {
			i_size_write(inode, offset + to);
		}
		unlock_page(page);
		page_cache_release(page);
		if (error)
			goto out;
		curr++;
		offset += PAGE_CACHE_SIZE;
		from = 0;
	}

	gfs2_dinode_out(ip, dibh->b_data);
	mark_inode_dirty(inode);

	brelse(dibh);

out:
	return error;
}

static void calc_max_reserv(struct gfs2_inode *ip, loff_t max, loff_t *len,
			    unsigned int *data_blocks, unsigned int *ind_blocks)
{
	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
	unsigned int max_blocks = ip->i_alloc->al_rgd->rd_free_clone;
	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);

	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
		max_data -= tmp;
	}
	/* This calculation isn't the exact reverse of gfs2_write_calc_reserve,
	   so it might end up with fewer data blocks */
	if (max_data <= *data_blocks)
		return;
	*data_blocks = max_data;
	*ind_blocks = max_blocks - max_data;
	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
	if (*len > max) {
		*len = max;
		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
	}
}

static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
			   loff_t len)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_inode *ip = GFS2_I(inode);
	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
	loff_t bytes, max_bytes;
	struct gfs2_alloc *al;
	int error;
819
	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
820 821 822 823 824 825 826
	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;

	/* We only support the FALLOC_FL_KEEP_SIZE mode */
	if (mode & ~FALLOC_FL_KEEP_SIZE)
		return -EOPNOTSUPP;

827
	offset &= bsize_mask;
828 829 830 831 832

	len = next - offset;
	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
	if (!bytes)
		bytes = UINT_MAX;
833 834 835
	bytes &= bsize_mask;
	if (bytes == 0)
		bytes = sdp->sd_sb.sb_bsize;
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865

	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
	error = gfs2_glock_nq(&ip->i_gh);
	if (unlikely(error))
		goto out_uninit;

	if (!gfs2_write_alloc_required(ip, offset, len))
		goto out_unlock;

	while (len > 0) {
		if (len < bytes)
			bytes = len;
		al = gfs2_alloc_get(ip);
		if (!al) {
			error = -ENOMEM;
			goto out_unlock;
		}

		error = gfs2_quota_lock_check(ip);
		if (error)
			goto out_alloc_put;

retry:
		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);

		al->al_requested = data_blocks + ind_blocks;
		error = gfs2_inplace_reserve(ip);
		if (error) {
			if (error == -ENOSPC && bytes > sdp->sd_sb.sb_bsize) {
				bytes >>= 1;
866 867 868
				bytes &= bsize_mask;
				if (bytes == 0)
					bytes = sdp->sd_sb.sb_bsize;
869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913
				goto retry;
			}
			goto out_qunlock;
		}
		max_bytes = bytes;
		calc_max_reserv(ip, len, &max_bytes, &data_blocks, &ind_blocks);
		al->al_requested = data_blocks + ind_blocks;

		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
			  RES_RG_HDR + gfs2_rg_blocks(al);
		if (gfs2_is_jdata(ip))
			rblocks += data_blocks ? data_blocks : 1;

		error = gfs2_trans_begin(sdp, rblocks,
					 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
		if (error)
			goto out_trans_fail;

		error = fallocate_chunk(inode, offset, max_bytes, mode);
		gfs2_trans_end(sdp);

		if (error)
			goto out_trans_fail;

		len -= max_bytes;
		offset += max_bytes;
		gfs2_inplace_release(ip);
		gfs2_quota_unlock(ip);
		gfs2_alloc_put(ip);
	}
	goto out_unlock;

out_trans_fail:
	gfs2_inplace_release(ip);
out_qunlock:
	gfs2_quota_unlock(ip);
out_alloc_put:
	gfs2_alloc_put(ip);
out_unlock:
	gfs2_glock_dq(&ip->i_gh);
out_uninit:
	gfs2_holder_uninit(&ip->i_gh);
	return error;
}

914 915
#ifdef CONFIG_GFS2_FS_LOCKING_DLM

916 917 918 919 920 921
/**
 * gfs2_setlease - acquire/release a file lease
 * @file: the file pointer
 * @arg: lease type
 * @fl: file lock
 *
922 923 924 925
 * We don't currently have a way to enforce a lease across the whole
 * cluster; until we do, disable leases (by just returning -EINVAL),
 * unless the administrator has requested purely local locking.
 *
926 927
 * Locking: called under lock_flocks
 *
928 929 930 931 932
 * Returns: errno
 */

static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
{
933
	return -EINVAL;
934 935
}

D
David Teigland 已提交
936 937 938 939 940 941 942 943 944 945 946
/**
 * gfs2_lock - acquire/release a posix lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
{
947 948
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
949
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
D
David Teigland 已提交
950 951 952

	if (!(fl->fl_flags & FL_POSIX))
		return -ENOLCK;
953
	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
D
David Teigland 已提交
954 955
		return -ENOLCK;

M
Marc Eshel 已提交
956 957 958 959 960
	if (cmd == F_CANCELLK) {
		/* Hack: */
		cmd = F_SETLK;
		fl->fl_type = F_UNLCK;
	}
961 962
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		return -EIO;
D
David Teigland 已提交
963
	if (IS_GETLK(cmd))
964
		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
D
David Teigland 已提交
965
	else if (fl->fl_type == F_UNLCK)
966
		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
D
David Teigland 已提交
967
	else
968
		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
D
David Teigland 已提交
969 970 971 972
}

static int do_flock(struct file *file, int cmd, struct file_lock *fl)
{
973
	struct gfs2_file *fp = file->private_data;
D
David Teigland 已提交
974
	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
J
Josef Sipek 已提交
975
	struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
D
David Teigland 已提交
976 977 978 979 980 981
	struct gfs2_glock *gl;
	unsigned int state;
	int flags;
	int error = 0;

	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
982
	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
D
David Teigland 已提交
983

984
	mutex_lock(&fp->f_fl_mutex);
D
David Teigland 已提交
985 986 987 988 989 990

	gl = fl_gh->gh_gl;
	if (gl) {
		if (fl_gh->gh_state == state)
			goto out;
		flock_lock_file_wait(file,
991
				     &(struct file_lock){.fl_type = F_UNLCK});
992 993
		gfs2_glock_dq_wait(fl_gh);
		gfs2_holder_reinit(state, flags, fl_gh);
D
David Teigland 已提交
994
	} else {
995 996
		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
				       &gfs2_flock_glops, CREATE, &gl);
D
David Teigland 已提交
997 998
		if (error)
			goto out;
999 1000
		gfs2_holder_init(gl, state, flags, fl_gh);
		gfs2_glock_put(gl);
D
David Teigland 已提交
1001 1002 1003 1004 1005 1006 1007 1008
	}
	error = gfs2_glock_nq(fl_gh);
	if (error) {
		gfs2_holder_uninit(fl_gh);
		if (error == GLR_TRYFAILED)
			error = -EAGAIN;
	} else {
		error = flock_lock_file_wait(file, fl);
1009
		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
D
David Teigland 已提交
1010 1011
	}

1012
out:
1013
	mutex_unlock(&fp->f_fl_mutex);
D
David Teigland 已提交
1014 1015 1016 1017 1018
	return error;
}

static void do_unflock(struct file *file, struct file_lock *fl)
{
1019
	struct gfs2_file *fp = file->private_data;
D
David Teigland 已提交
1020 1021
	struct gfs2_holder *fl_gh = &fp->f_fl_gh;

1022
	mutex_lock(&fp->f_fl_mutex);
D
David Teigland 已提交
1023
	flock_lock_file_wait(file, fl);
1024 1025 1026 1027
	if (fl_gh->gh_gl) {
		gfs2_glock_dq_wait(fl_gh);
		gfs2_holder_uninit(fl_gh);
	}
1028
	mutex_unlock(&fp->f_fl_mutex);
D
David Teigland 已提交
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
}

/**
 * gfs2_flock - acquire/release a flock lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
{
	if (!(fl->fl_flags & FL_FLOCK))
		return -ENOLCK;
1044 1045
	if (fl->fl_type & LOCK_MAND)
		return -EOPNOTSUPP;
D
David Teigland 已提交
1046 1047 1048 1049

	if (fl->fl_type == F_UNLCK) {
		do_unflock(file, fl);
		return 0;
1050
	} else {
D
David Teigland 已提交
1051
		return do_flock(file, cmd, fl);
1052
	}
D
David Teigland 已提交
1053 1054
}

1055
const struct file_operations gfs2_file_fops = {
1056
	.llseek		= gfs2_llseek,
1057
	.read		= do_sync_read,
1058
	.aio_read	= generic_file_aio_read,
1059
	.write		= do_sync_write,
1060
	.aio_write	= gfs2_file_aio_write,
1061 1062 1063 1064 1065 1066 1067 1068 1069
	.unlocked_ioctl	= gfs2_ioctl,
	.mmap		= gfs2_mmap,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.flock		= gfs2_flock,
	.splice_read	= generic_file_splice_read,
	.splice_write	= generic_file_splice_write,
1070
	.setlease	= gfs2_setlease,
1071
	.fallocate	= gfs2_fallocate,
D
David Teigland 已提交
1072 1073
};

1074
const struct file_operations gfs2_dir_fops = {
1075 1076 1077 1078 1079 1080 1081
	.readdir	= gfs2_readdir,
	.unlocked_ioctl	= gfs2_ioctl,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.flock		= gfs2_flock,
1082
	.llseek		= default_llseek,
D
David Teigland 已提交
1083 1084
};

1085 1086
#endif /* CONFIG_GFS2_FS_LOCKING_DLM */

1087
const struct file_operations gfs2_file_fops_nolock = {
1088 1089 1090 1091
	.llseek		= gfs2_llseek,
	.read		= do_sync_read,
	.aio_read	= generic_file_aio_read,
	.write		= do_sync_write,
1092
	.aio_write	= gfs2_file_aio_write,
1093 1094 1095 1096 1097 1098 1099
	.unlocked_ioctl	= gfs2_ioctl,
	.mmap		= gfs2_mmap,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
	.splice_read	= generic_file_splice_read,
	.splice_write	= generic_file_splice_write,
1100
	.setlease	= generic_setlease,
1101
	.fallocate	= gfs2_fallocate,
1102 1103
};

1104
const struct file_operations gfs2_dir_fops_nolock = {
1105 1106 1107 1108 1109
	.readdir	= gfs2_readdir,
	.unlocked_ioctl	= gfs2_ioctl,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
1110
	.llseek		= default_llseek,
1111 1112
};