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v3.1
 
   1/*
   2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4 *
   5 * This copyrighted material is made available to anyone wishing to use,
   6 * modify, copy, or redistribute it subject to the terms and conditions
   7 * of the GNU General Public License version 2.
   8 */
   9
  10#include <linux/slab.h>
  11#include <linux/spinlock.h>
  12#include <linux/completion.h>
  13#include <linux/buffer_head.h>
  14#include <linux/pagemap.h>
  15#include <linux/uio.h>
  16#include <linux/blkdev.h>
  17#include <linux/mm.h>
  18#include <linux/mount.h>
  19#include <linux/fs.h>
  20#include <linux/gfs2_ondisk.h>
  21#include <linux/ext2_fs.h>
  22#include <linux/falloc.h>
  23#include <linux/swap.h>
  24#include <linux/crc32.h>
  25#include <linux/writeback.h>
  26#include <asm/uaccess.h>
  27#include <linux/dlm.h>
  28#include <linux/dlm_plock.h>
 
 
  29
  30#include "gfs2.h"
  31#include "incore.h"
  32#include "bmap.h"
 
  33#include "dir.h"
  34#include "glock.h"
  35#include "glops.h"
  36#include "inode.h"
  37#include "log.h"
  38#include "meta_io.h"
  39#include "quota.h"
  40#include "rgrp.h"
  41#include "trans.h"
  42#include "util.h"
  43
  44/**
  45 * gfs2_llseek - seek to a location in a file
  46 * @file: the file
  47 * @offset: the offset
  48 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
  49 *
  50 * SEEK_END requires the glock for the file because it references the
  51 * file's size.
  52 *
  53 * Returns: The new offset, or errno
  54 */
  55
  56static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
  57{
  58	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
  59	struct gfs2_holder i_gh;
  60	loff_t error;
  61
  62	if (origin == 2) {
 
  63		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
  64					   &i_gh);
  65		if (!error) {
  66			error = generic_file_llseek_unlocked(file, offset, origin);
  67			gfs2_glock_dq_uninit(&i_gh);
  68		}
  69	} else
  70		error = generic_file_llseek_unlocked(file, offset, origin);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  71
  72	return error;
  73}
  74
  75/**
  76 * gfs2_readdir - Read directory entries from a directory
  77 * @file: The directory to read from
  78 * @dirent: Buffer for dirents
  79 * @filldir: Function used to do the copying
  80 *
  81 * Returns: errno
  82 */
  83
  84static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
  85{
  86	struct inode *dir = file->f_mapping->host;
  87	struct gfs2_inode *dip = GFS2_I(dir);
  88	struct gfs2_holder d_gh;
  89	u64 offset = file->f_pos;
  90	int error;
  91
  92	gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
  93	error = gfs2_glock_nq(&d_gh);
  94	if (error) {
  95		gfs2_holder_uninit(&d_gh);
  96		return error;
  97	}
  98
  99	error = gfs2_dir_read(dir, &offset, dirent, filldir);
 100
 101	gfs2_glock_dq_uninit(&d_gh);
 102
 103	file->f_pos = offset;
 104
 105	return error;
 106}
 107
 108/**
 109 * fsflags_cvt
 110 * @table: A table of 32 u32 flags
 111 * @val: a 32 bit value to convert
 112 *
 113 * This function can be used to convert between fsflags values and
 114 * GFS2's own flags values.
 115 *
 116 * Returns: the converted flags
 
 117 */
 118static u32 fsflags_cvt(const u32 *table, u32 val)
 119{
 120	u32 res = 0;
 121	while(val) {
 122		if (val & 1)
 123			res |= *table;
 124		table++;
 125		val >>= 1;
 126	}
 127	return res;
 128}
 129
 130static const u32 fsflags_to_gfs2[32] = {
 131	[3] = GFS2_DIF_SYNC,
 132	[4] = GFS2_DIF_IMMUTABLE,
 133	[5] = GFS2_DIF_APPENDONLY,
 134	[7] = GFS2_DIF_NOATIME,
 135	[12] = GFS2_DIF_EXHASH,
 136	[14] = GFS2_DIF_INHERIT_JDATA,
 137};
 138
 139static const u32 gfs2_to_fsflags[32] = {
 140	[gfs2fl_Sync] = FS_SYNC_FL,
 141	[gfs2fl_Immutable] = FS_IMMUTABLE_FL,
 142	[gfs2fl_AppendOnly] = FS_APPEND_FL,
 143	[gfs2fl_NoAtime] = FS_NOATIME_FL,
 144	[gfs2fl_ExHash] = FS_INDEX_FL,
 145	[gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
 146};
 
 
 
 
 
 
 
 147
 148static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
 149{
 150	struct inode *inode = filp->f_path.dentry->d_inode;
 151	struct gfs2_inode *ip = GFS2_I(inode);
 152	struct gfs2_holder gh;
 153	int error;
 154	u32 fsflags;
 155
 156	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 157	error = gfs2_glock_nq(&gh);
 158	if (error)
 159		return error;
 
 
 160
 161	fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_diskflags);
 162	if (!S_ISDIR(inode->i_mode) && ip->i_diskflags & GFS2_DIF_JDATA)
 163		fsflags |= FS_JOURNAL_DATA_FL;
 164	if (put_user(fsflags, ptr))
 165		error = -EFAULT;
 166
 167	gfs2_glock_dq(&gh);
 
 168	gfs2_holder_uninit(&gh);
 169	return error;
 170}
 171
 172void gfs2_set_inode_flags(struct inode *inode)
 173{
 174	struct gfs2_inode *ip = GFS2_I(inode);
 175	unsigned int flags = inode->i_flags;
 176
 177	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
 178	if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
 179		inode->i_flags |= S_NOSEC;
 180	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
 181		flags |= S_IMMUTABLE;
 182	if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
 183		flags |= S_APPEND;
 184	if (ip->i_diskflags & GFS2_DIF_NOATIME)
 185		flags |= S_NOATIME;
 186	if (ip->i_diskflags & GFS2_DIF_SYNC)
 187		flags |= S_SYNC;
 188	inode->i_flags = flags;
 189}
 190
 191/* Flags that can be set by user space */
 192#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
 193			     GFS2_DIF_IMMUTABLE|		\
 194			     GFS2_DIF_APPENDONLY|		\
 195			     GFS2_DIF_NOATIME|			\
 196			     GFS2_DIF_SYNC|			\
 197			     GFS2_DIF_SYSTEM|			\
 198			     GFS2_DIF_INHERIT_JDATA)
 199
 200/**
 201 * gfs2_set_flags - set flags on an inode
 202 * @inode: The inode
 203 * @flags: The flags to set
 204 * @mask: Indicates which flags are valid
 
 205 *
 206 */
 207static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
 
 208{
 209	struct inode *inode = filp->f_path.dentry->d_inode;
 210	struct gfs2_inode *ip = GFS2_I(inode);
 211	struct gfs2_sbd *sdp = GFS2_SB(inode);
 212	struct buffer_head *bh;
 213	struct gfs2_holder gh;
 214	int error;
 215	u32 new_flags, flags;
 216
 217	error = mnt_want_write(filp->f_path.mnt);
 218	if (error)
 219		return error;
 220
 221	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 222	if (error)
 223		goto out_drop_write;
 224
 
 
 
 
 
 225	error = -EACCES;
 226	if (!inode_owner_or_capable(inode))
 227		goto out;
 228
 229	error = 0;
 230	flags = ip->i_diskflags;
 231	new_flags = (flags & ~mask) | (reqflags & mask);
 232	if ((new_flags ^ flags) == 0)
 233		goto out;
 234
 235	error = -EINVAL;
 236	if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
 237		goto out;
 238
 239	error = -EPERM;
 240	if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
 241		goto out;
 242	if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
 243		goto out;
 244	if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
 245	    !capable(CAP_LINUX_IMMUTABLE))
 246		goto out;
 247	if (!IS_IMMUTABLE(inode)) {
 248		error = gfs2_permission(inode, MAY_WRITE);
 249		if (error)
 250			goto out;
 251	}
 252	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 253		if (flags & GFS2_DIF_JDATA)
 254			gfs2_log_flush(sdp, ip->i_gl);
 
 
 255		error = filemap_fdatawrite(inode->i_mapping);
 256		if (error)
 257			goto out;
 258		error = filemap_fdatawait(inode->i_mapping);
 259		if (error)
 260			goto out;
 
 
 261	}
 262	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 263	if (error)
 264		goto out;
 265	error = gfs2_meta_inode_buffer(ip, &bh);
 266	if (error)
 267		goto out_trans_end;
 268	gfs2_trans_add_bh(ip->i_gl, bh, 1);
 
 269	ip->i_diskflags = new_flags;
 270	gfs2_dinode_out(ip, bh->b_data);
 271	brelse(bh);
 272	gfs2_set_inode_flags(inode);
 273	gfs2_set_aops(inode);
 274out_trans_end:
 275	gfs2_trans_end(sdp);
 276out:
 277	gfs2_glock_dq_uninit(&gh);
 278out_drop_write:
 279	mnt_drop_write(filp->f_path.mnt);
 280	return error;
 281}
 282
 283static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 284{
 285	struct inode *inode = filp->f_path.dentry->d_inode;
 286	u32 fsflags, gfsflags;
 
 
 287
 288	if (get_user(fsflags, ptr))
 289		return -EFAULT;
 290
 291	gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
 292	if (!S_ISDIR(inode->i_mode)) {
 293		if (gfsflags & GFS2_DIF_INHERIT_JDATA)
 294			gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
 295		return do_gfs2_set_flags(filp, gfsflags, ~0);
 
 
 
 
 
 
 
 
 
 
 
 
 296	}
 297	return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
 
 
 
 
 
 
 
 
 
 
 
 
 298}
 299
 300static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 301{
 302	switch(cmd) {
 303	case FS_IOC_GETFLAGS:
 304		return gfs2_get_flags(filp, (u32 __user *)arg);
 305	case FS_IOC_SETFLAGS:
 306		return gfs2_set_flags(filp, (u32 __user *)arg);
 
 
 
 
 307	}
 
 308	return -ENOTTY;
 309}
 310
 311/**
 312 * gfs2_allocate_page_backing - Use bmap to allocate blocks
 313 * @page: The (locked) page to allocate backing for
 
 
 
 
 
 
 314 *
 315 * We try to allocate all the blocks required for the page in
 316 * one go. This might fail for various reasons, so we keep
 317 * trying until all the blocks to back this page are allocated.
 318 * If some of the blocks are already allocated, thats ok too.
 319 */
 320
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 321static int gfs2_allocate_page_backing(struct page *page)
 322{
 323	struct inode *inode = page->mapping->host;
 324	struct buffer_head bh;
 325	unsigned long size = PAGE_CACHE_SIZE;
 326	u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
 327
 328	do {
 329		bh.b_state = 0;
 330		bh.b_size = size;
 331		gfs2_block_map(inode, lblock, &bh, 1);
 332		if (!buffer_mapped(&bh))
 333			return -EIO;
 334		size -= bh.b_size;
 335		lblock += (bh.b_size >> inode->i_blkbits);
 336	} while(size > 0);
 
 
 
 337	return 0;
 338}
 339
 340/**
 341 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
 342 * @vma: The virtual memory area
 343 * @page: The page which is about to become writable
 344 *
 345 * When the page becomes writable, we need to ensure that we have
 346 * blocks allocated on disk to back that page.
 347 */
 348
 349static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 350{
 351	struct page *page = vmf->page;
 352	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 353	struct gfs2_inode *ip = GFS2_I(inode);
 354	struct gfs2_sbd *sdp = GFS2_SB(inode);
 
 355	unsigned long last_index;
 356	u64 pos = page->index << PAGE_CACHE_SHIFT;
 357	unsigned int data_blocks, ind_blocks, rblocks;
 358	struct gfs2_holder gh;
 359	struct gfs2_alloc *al;
 360	int ret;
 361
 
 
 
 
 
 
 
 
 362	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 363	ret = gfs2_glock_nq(&gh);
 364	if (ret)
 365		goto out;
 
 
 
 366
 367	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 368	set_bit(GIF_SW_PAGED, &ip->i_flags);
 369
 370	if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE))
 
 
 
 
 
 371		goto out_unlock;
 372	ret = -ENOMEM;
 373	al = gfs2_alloc_get(ip);
 374	if (al == NULL)
 
 375		goto out_unlock;
 376
 377	ret = gfs2_quota_lock_check(ip);
 
 
 378	if (ret)
 379		goto out_alloc_put;
 380	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
 381	al->al_requested = data_blocks + ind_blocks;
 382	ret = gfs2_inplace_reserve(ip);
 383	if (ret)
 384		goto out_quota_unlock;
 385
 386	rblocks = RES_DINODE + ind_blocks;
 387	if (gfs2_is_jdata(ip))
 388		rblocks += data_blocks ? data_blocks : 1;
 389	if (ind_blocks || data_blocks) {
 390		rblocks += RES_STATFS + RES_QUOTA;
 391		rblocks += gfs2_rg_blocks(al);
 392	}
 393	ret = gfs2_trans_begin(sdp, rblocks, 0);
 394	if (ret)
 395		goto out_trans_fail;
 396
 397	lock_page(page);
 398	ret = -EINVAL;
 399	last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
 400	if (page->index > last_index)
 401		goto out_unlock_page;
 
 
 
 
 
 
 
 
 
 
 
 402	ret = 0;
 403	if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
 404		goto out_unlock_page;
 405	if (gfs2_is_stuffed(ip)) {
 406		ret = gfs2_unstuff_dinode(ip, page);
 407		if (ret)
 408			goto out_unlock_page;
 409	}
 410	ret = gfs2_allocate_page_backing(page);
 411
 412out_unlock_page:
 413	unlock_page(page);
 
 414	gfs2_trans_end(sdp);
 415out_trans_fail:
 416	gfs2_inplace_release(ip);
 417out_quota_unlock:
 418	gfs2_quota_unlock(ip);
 419out_alloc_put:
 420	gfs2_alloc_put(ip);
 421out_unlock:
 422	gfs2_glock_dq(&gh);
 423out:
 424	gfs2_holder_uninit(&gh);
 425	if (ret == -ENOMEM)
 426		ret = VM_FAULT_OOM;
 427	else if (ret)
 428		ret = VM_FAULT_SIGBUS;
 429	return ret;
 
 
 430}
 431
 432static const struct vm_operations_struct gfs2_vm_ops = {
 433	.fault = filemap_fault,
 
 434	.page_mkwrite = gfs2_page_mkwrite,
 435};
 436
 437/**
 438 * gfs2_mmap -
 439 * @file: The file to map
 440 * @vma: The VMA which described the mapping
 441 *
 442 * There is no need to get a lock here unless we should be updating
 443 * atime. We ignore any locking errors since the only consequence is
 444 * a missed atime update (which will just be deferred until later).
 445 *
 446 * Returns: 0
 447 */
 448
 449static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 450{
 451	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 452
 453	if (!(file->f_flags & O_NOATIME) &&
 454	    !IS_NOATIME(&ip->i_inode)) {
 455		struct gfs2_holder i_gh;
 456		int error;
 457
 458		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 459		error = gfs2_glock_nq(&i_gh);
 460		if (error == 0) {
 461			file_accessed(file);
 462			gfs2_glock_dq(&i_gh);
 463		}
 464		gfs2_holder_uninit(&i_gh);
 465		if (error)
 466			return error;
 
 
 
 467	}
 468	vma->vm_ops = &gfs2_vm_ops;
 469	vma->vm_flags |= VM_CAN_NONLINEAR;
 470
 471	return 0;
 472}
 473
 474/**
 475 * gfs2_open - open a file
 476 * @inode: the inode to open
 477 * @file: the struct file for this opening
 
 
 
 
 
 478 *
 479 * Returns: errno
 480 */
 481
 482static int gfs2_open(struct inode *inode, struct file *file)
 483{
 484	struct gfs2_inode *ip = GFS2_I(inode);
 485	struct gfs2_holder i_gh;
 486	struct gfs2_file *fp;
 487	int error;
 
 
 
 
 
 
 488
 489	fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
 490	if (!fp)
 491		return -ENOMEM;
 492
 493	mutex_init(&fp->f_fl_mutex);
 494
 495	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
 496	file->private_data = fp;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 497
 498	if (S_ISREG(ip->i_inode.i_mode)) {
 499		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 500					   &i_gh);
 501		if (error)
 502			goto fail;
 
 
 503
 504		if (!(file->f_flags & O_LARGEFILE) &&
 505		    i_size_read(inode) > MAX_NON_LFS) {
 506			error = -EOVERFLOW;
 507			goto fail_gunlock;
 508		}
 509
 
 510		gfs2_glock_dq_uninit(&i_gh);
 511	}
 512
 513	return 0;
 514
 515fail_gunlock:
 516	gfs2_glock_dq_uninit(&i_gh);
 517fail:
 518	file->private_data = NULL;
 519	kfree(fp);
 520	return error;
 521}
 522
 523/**
 524 * gfs2_close - called to close a struct file
 525 * @inode: the inode the struct file belongs to
 526 * @file: the struct file being closed
 527 *
 528 * Returns: errno
 529 */
 530
 531static int gfs2_close(struct inode *inode, struct file *file)
 532{
 533	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
 534	struct gfs2_file *fp;
 535
 536	fp = file->private_data;
 537	file->private_data = NULL;
 538
 539	if (gfs2_assert_warn(sdp, fp))
 540		return -EIO;
 541
 542	kfree(fp);
 543
 
 544	return 0;
 545}
 546
 547/**
 548 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 549 * @file: the file that points to the dentry
 550 * @start: the start position in the file to sync
 551 * @end: the end position in the file to sync
 552 * @datasync: set if we can ignore timestamp changes
 553 *
 554 * The VFS will flush data for us. We only need to worry
 555 * about metadata here.
 
 
 
 
 
 
 
 
 556 *
 557 * Returns: errno
 558 */
 559
 560static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 561		      int datasync)
 562{
 563	struct inode *inode = file->f_mapping->host;
 564	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
 
 565	struct gfs2_inode *ip = GFS2_I(inode);
 566	int ret;
 567
 568	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 569	if (ret)
 570		return ret;
 571	mutex_lock(&inode->i_mutex);
 
 572
 
 
 573	if (datasync)
 574		sync_state &= ~I_DIRTY_SYNC;
 575
 576	if (sync_state) {
 577		ret = sync_inode_metadata(inode, 1);
 578		if (ret) {
 579			mutex_unlock(&inode->i_mutex);
 580			return ret;
 581		}
 582		gfs2_ail_flush(ip->i_gl);
 
 
 
 583	}
 584
 585	mutex_unlock(&inode->i_mutex);
 586	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 587}
 588
 589/**
 590 * gfs2_file_aio_write - Perform a write to a file
 591 * @iocb: The io context
 592 * @iov: The data to write
 593 * @nr_segs: Number of @iov segments
 594 * @pos: The file position
 595 *
 596 * We have to do a lock/unlock here to refresh the inode size for
 597 * O_APPEND writes, otherwise we can land up writing at the wrong
 598 * offset. There is still a race, but provided the app is using its
 599 * own file locking, this will make O_APPEND work as expected.
 600 *
 601 */
 602
 603static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 604				   unsigned long nr_segs, loff_t pos)
 605{
 606	struct file *file = iocb->ki_filp;
 
 
 
 
 
 
 
 
 
 607
 608	if (file->f_flags & O_APPEND) {
 609		struct dentry *dentry = file->f_dentry;
 610		struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
 611		struct gfs2_holder gh;
 612		int ret;
 613
 614		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 615		if (ret)
 616			return ret;
 617		gfs2_glock_dq_uninit(&gh);
 618	}
 619
 620	return generic_file_aio_write(iocb, iov, nr_segs, pos);
 621}
 
 
 622
 623static int empty_write_end(struct page *page, unsigned from,
 624			   unsigned to, int mode)
 625{
 626	struct inode *inode = page->mapping->host;
 627	struct gfs2_inode *ip = GFS2_I(inode);
 628	struct buffer_head *bh;
 629	unsigned offset, blksize = 1 << inode->i_blkbits;
 630	pgoff_t end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
 631
 632	zero_user(page, from, to-from);
 633	mark_page_accessed(page);
 
 634
 635	if (page->index < end_index || !(mode & FALLOC_FL_KEEP_SIZE)) {
 636		if (!gfs2_is_writeback(ip))
 637			gfs2_page_add_databufs(ip, page, from, to);
 638
 639		block_commit_write(page, from, to);
 640		return 0;
 641	}
 
 
 
 
 
 642
 643	offset = 0;
 644	bh = page_buffers(page);
 645	while (offset < to) {
 646		if (offset >= from) {
 647			set_buffer_uptodate(bh);
 648			mark_buffer_dirty(bh);
 649			clear_buffer_new(bh);
 650			write_dirty_buffer(bh, WRITE);
 651		}
 652		offset += blksize;
 653		bh = bh->b_this_page;
 654	}
 655
 656	offset = 0;
 657	bh = page_buffers(page);
 658	while (offset < to) {
 659		if (offset >= from) {
 660			wait_on_buffer(bh);
 661			if (!buffer_uptodate(bh))
 662				return -EIO;
 
 
 
 
 
 
 
 
 
 
 
 
 663		}
 664		offset += blksize;
 665		bh = bh->b_this_page;
 
 
 666	}
 667	return 0;
 668}
 669
 670static int needs_empty_write(sector_t block, struct inode *inode)
 671{
 672	int error;
 673	struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 674
 675	bh_map.b_size = 1 << inode->i_blkbits;
 676	error = gfs2_block_map(inode, block, &bh_map, 0);
 677	if (unlikely(error))
 678		return error;
 679	return !buffer_mapped(&bh_map);
 680}
 681
 682static int write_empty_blocks(struct page *page, unsigned from, unsigned to,
 683			      int mode)
 684{
 685	struct inode *inode = page->mapping->host;
 686	unsigned start, end, next, blksize;
 687	sector_t block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
 688	int ret;
 689
 690	blksize = 1 << inode->i_blkbits;
 691	next = end = 0;
 692	while (next < from) {
 693		next += blksize;
 694		block++;
 695	}
 696	start = next;
 697	do {
 698		next += blksize;
 699		ret = needs_empty_write(block, inode);
 700		if (unlikely(ret < 0))
 701			return ret;
 702		if (ret == 0) {
 703			if (end) {
 704				ret = __block_write_begin(page, start, end - start,
 705							  gfs2_block_map);
 706				if (unlikely(ret))
 707					return ret;
 708				ret = empty_write_end(page, start, end, mode);
 709				if (unlikely(ret))
 710					return ret;
 711				end = 0;
 712			}
 713			start = next;
 714		}
 715		else
 716			end = next;
 717		block++;
 718	} while (next < to);
 719
 720	if (end) {
 721		ret = __block_write_begin(page, start, end - start, gfs2_block_map);
 722		if (unlikely(ret))
 723			return ret;
 724		ret = empty_write_end(page, start, end, mode);
 725		if (unlikely(ret))
 726			return ret;
 727	}
 728
 729	return 0;
 730}
 731
 732static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
 733			   int mode)
 734{
 
 735	struct gfs2_inode *ip = GFS2_I(inode);
 
 736	struct buffer_head *dibh;
 737	int error;
 738	u64 start = offset >> PAGE_CACHE_SHIFT;
 739	unsigned int start_offset = offset & ~PAGE_CACHE_MASK;
 740	u64 end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 741	pgoff_t curr;
 742	struct page *page;
 743	unsigned int end_offset = (offset + len) & ~PAGE_CACHE_MASK;
 744	unsigned int from, to;
 745
 746	if (!end_offset)
 747		end_offset = PAGE_CACHE_SIZE;
 748
 749	error = gfs2_meta_inode_buffer(ip, &dibh);
 750	if (unlikely(error))
 751		goto out;
 752
 753	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 754
 755	if (gfs2_is_stuffed(ip)) {
 756		error = gfs2_unstuff_dinode(ip, NULL);
 757		if (unlikely(error))
 758			goto out;
 759	}
 760
 761	curr = start;
 762	offset = start << PAGE_CACHE_SHIFT;
 763	from = start_offset;
 764	to = PAGE_CACHE_SIZE;
 765	while (curr <= end) {
 766		page = grab_cache_page_write_begin(inode->i_mapping, curr,
 767						   AOP_FLAG_NOFS);
 768		if (unlikely(!page)) {
 769			error = -ENOMEM;
 770			goto out;
 771		}
 772
 773		if (curr == end)
 774			to = end_offset;
 775		error = write_empty_blocks(page, from, to, mode);
 776		if (!error && offset + to > inode->i_size &&
 777		    !(mode & FALLOC_FL_KEEP_SIZE)) {
 778			i_size_write(inode, offset + to);
 779		}
 780		unlock_page(page);
 781		page_cache_release(page);
 782		if (error)
 783			goto out;
 784		curr++;
 785		offset += PAGE_CACHE_SIZE;
 786		from = 0;
 
 
 
 
 
 
 
 787	}
 788
 789	gfs2_dinode_out(ip, dibh->b_data);
 790	mark_inode_dirty(inode);
 791
 792	brelse(dibh);
 793
 794out:
 
 795	return error;
 796}
 797
 798static void calc_max_reserv(struct gfs2_inode *ip, loff_t max, loff_t *len,
 799			    unsigned int *data_blocks, unsigned int *ind_blocks)
 
 
 
 
 
 
 
 
 
 
 
 800{
 
 801	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 802	unsigned int max_blocks = ip->i_alloc->al_rgd->rd_free_clone;
 803	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
 804
 805	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
 806		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
 807		max_data -= tmp;
 808	}
 809	/* This calculation isn't the exact reverse of gfs2_write_calc_reserve,
 810	   so it might end up with fewer data blocks */
 811	if (max_data <= *data_blocks)
 812		return;
 813	*data_blocks = max_data;
 814	*ind_blocks = max_blocks - max_data;
 815	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
 816	if (*len > max) {
 817		*len = max;
 818		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
 819	}
 820}
 821
 822static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
 823			   loff_t len)
 824{
 825	struct inode *inode = file->f_path.dentry->d_inode;
 826	struct gfs2_sbd *sdp = GFS2_SB(inode);
 827	struct gfs2_inode *ip = GFS2_I(inode);
 
 828	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
 829	loff_t bytes, max_bytes;
 830	struct gfs2_alloc *al;
 831	int error;
 
 
 832	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
 833	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
 834	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
 835
 836	/* We only support the FALLOC_FL_KEEP_SIZE mode */
 837	if (mode & ~FALLOC_FL_KEEP_SIZE)
 838		return -EOPNOTSUPP;
 839
 840	offset &= bsize_mask;
 841
 842	len = next - offset;
 843	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
 844	if (!bytes)
 845		bytes = UINT_MAX;
 846	bytes &= bsize_mask;
 847	if (bytes == 0)
 848		bytes = sdp->sd_sb.sb_bsize;
 849
 850	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
 851	error = gfs2_glock_nq(&ip->i_gh);
 852	if (unlikely(error))
 853		goto out_uninit;
 854
 855	if (!gfs2_write_alloc_required(ip, offset, len))
 856		goto out_unlock;
 857
 858	while (len > 0) {
 859		if (len < bytes)
 860			bytes = len;
 861		al = gfs2_alloc_get(ip);
 862		if (!al) {
 863			error = -ENOMEM;
 864			goto out_unlock;
 865		}
 866
 867		error = gfs2_quota_lock_check(ip);
 868		if (error)
 869			goto out_alloc_put;
 870
 871retry:
 
 
 
 
 
 872		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
 
 873
 874		al->al_requested = data_blocks + ind_blocks;
 875		error = gfs2_inplace_reserve(ip);
 876		if (error) {
 877			if (error == -ENOSPC && bytes > sdp->sd_sb.sb_bsize) {
 878				bytes >>= 1;
 879				bytes &= bsize_mask;
 880				if (bytes == 0)
 881					bytes = sdp->sd_sb.sb_bsize;
 882				goto retry;
 883			}
 
 884			goto out_qunlock;
 885		}
 886		max_bytes = bytes;
 887		calc_max_reserv(ip, len, &max_bytes, &data_blocks, &ind_blocks);
 888		al->al_requested = data_blocks + ind_blocks;
 
 
 
 
 
 
 889
 890		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
 891			  RES_RG_HDR + gfs2_rg_blocks(al);
 892		if (gfs2_is_jdata(ip))
 893			rblocks += data_blocks ? data_blocks : 1;
 894
 895		error = gfs2_trans_begin(sdp, rblocks,
 896					 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
 897		if (error)
 898			goto out_trans_fail;
 899
 900		error = fallocate_chunk(inode, offset, max_bytes, mode);
 901		gfs2_trans_end(sdp);
 902
 903		if (error)
 904			goto out_trans_fail;
 905
 906		len -= max_bytes;
 907		offset += max_bytes;
 908		gfs2_inplace_release(ip);
 909		gfs2_quota_unlock(ip);
 910		gfs2_alloc_put(ip);
 911	}
 912	goto out_unlock;
 
 
 
 
 
 
 
 
 
 913
 914out_trans_fail:
 915	gfs2_inplace_release(ip);
 916out_qunlock:
 917	gfs2_quota_unlock(ip);
 918out_alloc_put:
 919	gfs2_alloc_put(ip);
 920out_unlock:
 921	gfs2_glock_dq(&ip->i_gh);
 922out_uninit:
 923	gfs2_holder_uninit(&ip->i_gh);
 924	return error;
 925}
 926
 927#ifdef CONFIG_GFS2_FS_LOCKING_DLM
 
 
 
 
 
 
 928
 929/**
 930 * gfs2_setlease - acquire/release a file lease
 931 * @file: the file pointer
 932 * @arg: lease type
 933 * @fl: file lock
 934 *
 935 * We don't currently have a way to enforce a lease across the whole
 936 * cluster; until we do, disable leases (by just returning -EINVAL),
 937 * unless the administrator has requested purely local locking.
 938 *
 939 * Locking: called under lock_flocks
 940 *
 941 * Returns: errno
 942 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 943
 944static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 945{
 946	return -EINVAL;
 
 
 
 
 
 
 
 
 
 947}
 948
 
 
 949/**
 950 * gfs2_lock - acquire/release a posix lock on a file
 951 * @file: the file pointer
 952 * @cmd: either modify or retrieve lock state, possibly wait
 953 * @fl: type and range of lock
 954 *
 955 * Returns: errno
 956 */
 957
 958static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
 959{
 960	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 961	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
 962	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
 963
 964	if (!(fl->fl_flags & FL_POSIX))
 965		return -ENOLCK;
 966	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
 967		return -ENOLCK;
 968
 969	if (cmd == F_CANCELLK) {
 970		/* Hack: */
 971		cmd = F_SETLK;
 972		fl->fl_type = F_UNLCK;
 973	}
 974	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 
 
 975		return -EIO;
 
 976	if (IS_GETLK(cmd))
 977		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
 978	else if (fl->fl_type == F_UNLCK)
 979		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
 980	else
 981		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
 982}
 983
 984static int do_flock(struct file *file, int cmd, struct file_lock *fl)
 985{
 986	struct gfs2_file *fp = file->private_data;
 987	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
 988	struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
 989	struct gfs2_glock *gl;
 990	unsigned int state;
 991	int flags;
 992	int error = 0;
 
 993
 994	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
 995	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;
 996
 997	mutex_lock(&fp->f_fl_mutex);
 998
 999	gl = fl_gh->gh_gl;
1000	if (gl) {
1001		if (fl_gh->gh_state == state)
1002			goto out;
1003		flock_lock_file_wait(file,
1004				     &(struct file_lock){.fl_type = F_UNLCK});
1005		gfs2_glock_dq_wait(fl_gh);
 
 
1006		gfs2_holder_reinit(state, flags, fl_gh);
1007	} else {
1008		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
1009				       &gfs2_flock_glops, CREATE, &gl);
1010		if (error)
1011			goto out;
1012		gfs2_holder_init(gl, state, flags, fl_gh);
1013		gfs2_glock_put(gl);
1014	}
1015	error = gfs2_glock_nq(fl_gh);
 
 
 
 
 
 
 
1016	if (error) {
1017		gfs2_holder_uninit(fl_gh);
1018		if (error == GLR_TRYFAILED)
1019			error = -EAGAIN;
1020	} else {
1021		error = flock_lock_file_wait(file, fl);
1022		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
1023	}
1024
1025out:
1026	mutex_unlock(&fp->f_fl_mutex);
1027	return error;
1028}
1029
1030static void do_unflock(struct file *file, struct file_lock *fl)
1031{
1032	struct gfs2_file *fp = file->private_data;
1033	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1034
1035	mutex_lock(&fp->f_fl_mutex);
1036	flock_lock_file_wait(file, fl);
1037	if (fl_gh->gh_gl) {
1038		gfs2_glock_dq_wait(fl_gh);
1039		gfs2_holder_uninit(fl_gh);
1040	}
1041	mutex_unlock(&fp->f_fl_mutex);
1042}
1043
1044/**
1045 * gfs2_flock - acquire/release a flock lock on a file
1046 * @file: the file pointer
1047 * @cmd: either modify or retrieve lock state, possibly wait
1048 * @fl: type and range of lock
1049 *
1050 * Returns: errno
1051 */
1052
1053static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
1054{
1055	if (!(fl->fl_flags & FL_FLOCK))
1056		return -ENOLCK;
1057	if (fl->fl_type & LOCK_MAND)
1058		return -EOPNOTSUPP;
1059
1060	if (fl->fl_type == F_UNLCK) {
1061		do_unflock(file, fl);
1062		return 0;
1063	} else {
1064		return do_flock(file, cmd, fl);
1065	}
1066}
1067
1068const struct file_operations gfs2_file_fops = {
1069	.llseek		= gfs2_llseek,
1070	.read		= do_sync_read,
1071	.aio_read	= generic_file_aio_read,
1072	.write		= do_sync_write,
1073	.aio_write	= gfs2_file_aio_write,
1074	.unlocked_ioctl	= gfs2_ioctl,
1075	.mmap		= gfs2_mmap,
1076	.open		= gfs2_open,
1077	.release	= gfs2_close,
1078	.fsync		= gfs2_fsync,
1079	.lock		= gfs2_lock,
1080	.flock		= gfs2_flock,
1081	.splice_read	= generic_file_splice_read,
1082	.splice_write	= generic_file_splice_write,
1083	.setlease	= gfs2_setlease,
1084	.fallocate	= gfs2_fallocate,
1085};
1086
1087const struct file_operations gfs2_dir_fops = {
1088	.readdir	= gfs2_readdir,
1089	.unlocked_ioctl	= gfs2_ioctl,
1090	.open		= gfs2_open,
1091	.release	= gfs2_close,
1092	.fsync		= gfs2_fsync,
1093	.lock		= gfs2_lock,
1094	.flock		= gfs2_flock,
1095	.llseek		= default_llseek,
1096};
1097
1098#endif /* CONFIG_GFS2_FS_LOCKING_DLM */
1099
1100const struct file_operations gfs2_file_fops_nolock = {
1101	.llseek		= gfs2_llseek,
1102	.read		= do_sync_read,
1103	.aio_read	= generic_file_aio_read,
1104	.write		= do_sync_write,
1105	.aio_write	= gfs2_file_aio_write,
1106	.unlocked_ioctl	= gfs2_ioctl,
1107	.mmap		= gfs2_mmap,
1108	.open		= gfs2_open,
1109	.release	= gfs2_close,
1110	.fsync		= gfs2_fsync,
1111	.splice_read	= generic_file_splice_read,
1112	.splice_write	= generic_file_splice_write,
1113	.setlease	= generic_setlease,
1114	.fallocate	= gfs2_fallocate,
1115};
1116
1117const struct file_operations gfs2_dir_fops_nolock = {
1118	.readdir	= gfs2_readdir,
1119	.unlocked_ioctl	= gfs2_ioctl,
1120	.open		= gfs2_open,
1121	.release	= gfs2_close,
1122	.fsync		= gfs2_fsync,
1123	.llseek		= default_llseek,
1124};
1125
v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 
 
 
 
   5 */
   6
   7#include <linux/slab.h>
   8#include <linux/spinlock.h>
   9#include <linux/completion.h>
  10#include <linux/buffer_head.h>
  11#include <linux/pagemap.h>
  12#include <linux/uio.h>
  13#include <linux/blkdev.h>
  14#include <linux/mm.h>
  15#include <linux/mount.h>
  16#include <linux/fs.h>
  17#include <linux/gfs2_ondisk.h>
 
  18#include <linux/falloc.h>
  19#include <linux/swap.h>
  20#include <linux/crc32.h>
  21#include <linux/writeback.h>
  22#include <linux/uaccess.h>
  23#include <linux/dlm.h>
  24#include <linux/dlm_plock.h>
  25#include <linux/delay.h>
  26#include <linux/backing-dev.h>
  27
  28#include "gfs2.h"
  29#include "incore.h"
  30#include "bmap.h"
  31#include "aops.h"
  32#include "dir.h"
  33#include "glock.h"
  34#include "glops.h"
  35#include "inode.h"
  36#include "log.h"
  37#include "meta_io.h"
  38#include "quota.h"
  39#include "rgrp.h"
  40#include "trans.h"
  41#include "util.h"
  42
  43/**
  44 * gfs2_llseek - seek to a location in a file
  45 * @file: the file
  46 * @offset: the offset
  47 * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
  48 *
  49 * SEEK_END requires the glock for the file because it references the
  50 * file's size.
  51 *
  52 * Returns: The new offset, or errno
  53 */
  54
  55static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
  56{
  57	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
  58	struct gfs2_holder i_gh;
  59	loff_t error;
  60
  61	switch (whence) {
  62	case SEEK_END:
  63		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
  64					   &i_gh);
  65		if (!error) {
  66			error = generic_file_llseek(file, offset, whence);
  67			gfs2_glock_dq_uninit(&i_gh);
  68		}
  69		break;
  70
  71	case SEEK_DATA:
  72		error = gfs2_seek_data(file, offset);
  73		break;
  74
  75	case SEEK_HOLE:
  76		error = gfs2_seek_hole(file, offset);
  77		break;
  78
  79	case SEEK_CUR:
  80	case SEEK_SET:
  81		/*
  82		 * These don't reference inode->i_size and don't depend on the
  83		 * block mapping, so we don't need the glock.
  84		 */
  85		error = generic_file_llseek(file, offset, whence);
  86		break;
  87	default:
  88		error = -EINVAL;
  89	}
  90
  91	return error;
  92}
  93
  94/**
  95 * gfs2_readdir - Iterator for a directory
  96 * @file: The directory to read from
  97 * @ctx: What to feed directory entries to
 
  98 *
  99 * Returns: errno
 100 */
 101
 102static int gfs2_readdir(struct file *file, struct dir_context *ctx)
 103{
 104	struct inode *dir = file->f_mapping->host;
 105	struct gfs2_inode *dip = GFS2_I(dir);
 106	struct gfs2_holder d_gh;
 
 107	int error;
 108
 109	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
 110	if (error)
 
 
 111		return error;
 
 112
 113	error = gfs2_dir_read(dir, ctx, &file->f_ra);
 114
 115	gfs2_glock_dq_uninit(&d_gh);
 116
 
 
 117	return error;
 118}
 119
 120/**
 121 * fsflag_gfs2flag
 
 
 
 
 
 122 *
 123 * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories,
 124 * and to GFS2_DIF_JDATA for non-directories.
 125 */
 126static struct {
 127	u32 fsflag;
 128	u32 gfsflag;
 129} fsflag_gfs2flag[] = {
 130	{FS_SYNC_FL, GFS2_DIF_SYNC},
 131	{FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE},
 132	{FS_APPEND_FL, GFS2_DIF_APPENDONLY},
 133	{FS_NOATIME_FL, GFS2_DIF_NOATIME},
 134	{FS_INDEX_FL, GFS2_DIF_EXHASH},
 135	{FS_TOPDIR_FL, GFS2_DIF_TOPDIR},
 136	{FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
 
 
 
 
 
 
 
 
 137};
 138
 139static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
 140{
 141	int i;
 142	u32 fsflags = 0;
 143
 144	if (S_ISDIR(inode->i_mode))
 145		gfsflags &= ~GFS2_DIF_JDATA;
 146	else
 147		gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
 148
 149	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
 150		if (gfsflags & fsflag_gfs2flag[i].gfsflag)
 151			fsflags |= fsflag_gfs2flag[i].fsflag;
 152	return fsflags;
 153}
 154
 155static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
 156{
 157	struct inode *inode = file_inode(filp);
 158	struct gfs2_inode *ip = GFS2_I(inode);
 159	struct gfs2_holder gh;
 160	int error;
 161	u32 fsflags;
 162
 163	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 164	error = gfs2_glock_nq(&gh);
 165	if (error)
 166		goto out_uninit;
 167
 168	fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
 169
 
 
 
 170	if (put_user(fsflags, ptr))
 171		error = -EFAULT;
 172
 173	gfs2_glock_dq(&gh);
 174out_uninit:
 175	gfs2_holder_uninit(&gh);
 176	return error;
 177}
 178
 179void gfs2_set_inode_flags(struct inode *inode)
 180{
 181	struct gfs2_inode *ip = GFS2_I(inode);
 182	unsigned int flags = inode->i_flags;
 183
 184	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
 185	if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
 186		flags |= S_NOSEC;
 187	if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
 188		flags |= S_IMMUTABLE;
 189	if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
 190		flags |= S_APPEND;
 191	if (ip->i_diskflags & GFS2_DIF_NOATIME)
 192		flags |= S_NOATIME;
 193	if (ip->i_diskflags & GFS2_DIF_SYNC)
 194		flags |= S_SYNC;
 195	inode->i_flags = flags;
 196}
 197
 198/* Flags that can be set by user space */
 199#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
 200			     GFS2_DIF_IMMUTABLE|		\
 201			     GFS2_DIF_APPENDONLY|		\
 202			     GFS2_DIF_NOATIME|			\
 203			     GFS2_DIF_SYNC|			\
 204			     GFS2_DIF_TOPDIR|			\
 205			     GFS2_DIF_INHERIT_JDATA)
 206
 207/**
 208 * do_gfs2_set_flags - set flags on an inode
 209 * @filp: file pointer
 210 * @reqflags: The flags to set
 211 * @mask: Indicates which flags are valid
 212 * @fsflags: The FS_* inode flags passed in
 213 *
 214 */
 215static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask,
 216			     const u32 fsflags)
 217{
 218	struct inode *inode = file_inode(filp);
 219	struct gfs2_inode *ip = GFS2_I(inode);
 220	struct gfs2_sbd *sdp = GFS2_SB(inode);
 221	struct buffer_head *bh;
 222	struct gfs2_holder gh;
 223	int error;
 224	u32 new_flags, flags, oldflags;
 225
 226	error = mnt_want_write_file(filp);
 227	if (error)
 228		return error;
 229
 230	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 231	if (error)
 232		goto out_drop_write;
 233
 234	oldflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
 235	error = vfs_ioc_setflags_prepare(inode, oldflags, fsflags);
 236	if (error)
 237		goto out;
 238
 239	error = -EACCES;
 240	if (!inode_owner_or_capable(inode))
 241		goto out;
 242
 243	error = 0;
 244	flags = ip->i_diskflags;
 245	new_flags = (flags & ~mask) | (reqflags & mask);
 246	if ((new_flags ^ flags) == 0)
 247		goto out;
 248
 
 
 
 
 249	error = -EPERM;
 250	if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
 251		goto out;
 252	if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
 253		goto out;
 254	if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
 255	    !capable(CAP_LINUX_IMMUTABLE))
 256		goto out;
 257	if (!IS_IMMUTABLE(inode)) {
 258		error = gfs2_permission(inode, MAY_WRITE);
 259		if (error)
 260			goto out;
 261	}
 262	if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
 263		if (new_flags & GFS2_DIF_JDATA)
 264			gfs2_log_flush(sdp, ip->i_gl,
 265				       GFS2_LOG_HEAD_FLUSH_NORMAL |
 266				       GFS2_LFC_SET_FLAGS);
 267		error = filemap_fdatawrite(inode->i_mapping);
 268		if (error)
 269			goto out;
 270		error = filemap_fdatawait(inode->i_mapping);
 271		if (error)
 272			goto out;
 273		if (new_flags & GFS2_DIF_JDATA)
 274			gfs2_ordered_del_inode(ip);
 275	}
 276	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 277	if (error)
 278		goto out;
 279	error = gfs2_meta_inode_buffer(ip, &bh);
 280	if (error)
 281		goto out_trans_end;
 282	inode->i_ctime = current_time(inode);
 283	gfs2_trans_add_meta(ip->i_gl, bh);
 284	ip->i_diskflags = new_flags;
 285	gfs2_dinode_out(ip, bh->b_data);
 286	brelse(bh);
 287	gfs2_set_inode_flags(inode);
 288	gfs2_set_aops(inode);
 289out_trans_end:
 290	gfs2_trans_end(sdp);
 291out:
 292	gfs2_glock_dq_uninit(&gh);
 293out_drop_write:
 294	mnt_drop_write_file(filp);
 295	return error;
 296}
 297
 298static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 299{
 300	struct inode *inode = file_inode(filp);
 301	u32 fsflags, gfsflags = 0;
 302	u32 mask;
 303	int i;
 304
 305	if (get_user(fsflags, ptr))
 306		return -EFAULT;
 307
 308	for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) {
 309		if (fsflags & fsflag_gfs2flag[i].fsflag) {
 310			fsflags &= ~fsflag_gfs2flag[i].fsflag;
 311			gfsflags |= fsflag_gfs2flag[i].gfsflag;
 312		}
 313	}
 314	if (fsflags || gfsflags & ~GFS2_FLAGS_USER_SET)
 315		return -EINVAL;
 316
 317	mask = GFS2_FLAGS_USER_SET;
 318	if (S_ISDIR(inode->i_mode)) {
 319		mask &= ~GFS2_DIF_JDATA;
 320	} else {
 321		/* The GFS2_DIF_TOPDIR flag is only valid for directories. */
 322		if (gfsflags & GFS2_DIF_TOPDIR)
 323			return -EINVAL;
 324		mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA);
 325	}
 326
 327	return do_gfs2_set_flags(filp, gfsflags, mask, fsflags);
 328}
 329
 330static int gfs2_getlabel(struct file *filp, char __user *label)
 331{
 332	struct inode *inode = file_inode(filp);
 333	struct gfs2_sbd *sdp = GFS2_SB(inode);
 334
 335	if (copy_to_user(label, sdp->sd_sb.sb_locktable, GFS2_LOCKNAME_LEN))
 336		return -EFAULT;
 337
 338	return 0;
 339}
 340
 341static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 342{
 343	switch(cmd) {
 344	case FS_IOC_GETFLAGS:
 345		return gfs2_get_flags(filp, (u32 __user *)arg);
 346	case FS_IOC_SETFLAGS:
 347		return gfs2_set_flags(filp, (u32 __user *)arg);
 348	case FITRIM:
 349		return gfs2_fitrim(filp, (void __user *)arg);
 350	case FS_IOC_GETFSLABEL:
 351		return gfs2_getlabel(filp, (char __user *)arg);
 352	}
 353
 354	return -ENOTTY;
 355}
 356
 357/**
 358 * gfs2_size_hint - Give a hint to the size of a write request
 359 * @filep: The struct file
 360 * @offset: The file offset of the write
 361 * @size: The length of the write
 362 *
 363 * When we are about to do a write, this function records the total
 364 * write size in order to provide a suitable hint to the lower layers
 365 * about how many blocks will be required.
 366 *
 
 
 
 
 367 */
 368
 369static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size)
 370{
 371	struct inode *inode = file_inode(filep);
 372	struct gfs2_sbd *sdp = GFS2_SB(inode);
 373	struct gfs2_inode *ip = GFS2_I(inode);
 374	size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift;
 375	int hint = min_t(size_t, INT_MAX, blks);
 376
 377	if (hint > atomic_read(&ip->i_sizehint))
 378		atomic_set(&ip->i_sizehint, hint);
 379}
 380
 381/**
 382 * gfs2_allocate_page_backing - Allocate blocks for a write fault
 383 * @page: The (locked) page to allocate backing for
 384 *
 385 * We try to allocate all the blocks required for the page in one go.  This
 386 * might fail for various reasons, so we keep trying until all the blocks to
 387 * back this page are allocated.  If some of the blocks are already allocated,
 388 * that is ok too.
 389 */
 390static int gfs2_allocate_page_backing(struct page *page)
 391{
 392	u64 pos = page_offset(page);
 393	u64 size = PAGE_SIZE;
 
 
 394
 395	do {
 396		struct iomap iomap = { };
 397
 398		if (gfs2_iomap_get_alloc(page->mapping->host, pos, 1, &iomap))
 
 399			return -EIO;
 400
 401		iomap.length = min(iomap.length, size);
 402		size -= iomap.length;
 403		pos += iomap.length;
 404	} while (size > 0);
 405
 406	return 0;
 407}
 408
 409/**
 410 * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
 411 * @vma: The virtual memory area
 412 * @vmf: The virtual memory fault containing the page to become writable
 413 *
 414 * When the page becomes writable, we need to ensure that we have
 415 * blocks allocated on disk to back that page.
 416 */
 417
 418static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
 419{
 420	struct page *page = vmf->page;
 421	struct inode *inode = file_inode(vmf->vma->vm_file);
 422	struct gfs2_inode *ip = GFS2_I(inode);
 423	struct gfs2_sbd *sdp = GFS2_SB(inode);
 424	struct gfs2_alloc_parms ap = { .aflags = 0, };
 425	unsigned long last_index;
 426	u64 pos = page_offset(page);
 427	unsigned int data_blocks, ind_blocks, rblocks;
 428	struct gfs2_holder gh;
 429	loff_t size;
 430	int ret;
 431
 432	sb_start_pagefault(inode->i_sb);
 433
 434	ret = gfs2_rsqa_alloc(ip);
 435	if (ret)
 436		goto out;
 437
 438	gfs2_size_hint(vmf->vma->vm_file, pos, PAGE_SIZE);
 439
 440	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
 441	ret = gfs2_glock_nq(&gh);
 442	if (ret)
 443		goto out_uninit;
 444
 445	/* Update file times before taking page lock */
 446	file_update_time(vmf->vma->vm_file);
 447
 448	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
 449	set_bit(GIF_SW_PAGED, &ip->i_flags);
 450
 451	if (!gfs2_write_alloc_required(ip, pos, PAGE_SIZE)) {
 452		lock_page(page);
 453		if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
 454			ret = -EAGAIN;
 455			unlock_page(page);
 456		}
 457		goto out_unlock;
 458	}
 459
 460	ret = gfs2_rindex_update(sdp);
 461	if (ret)
 462		goto out_unlock;
 463
 464	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
 465	ap.target = data_blocks + ind_blocks;
 466	ret = gfs2_quota_lock_check(ip, &ap);
 467	if (ret)
 468		goto out_unlock;
 469	ret = gfs2_inplace_reserve(ip, &ap);
 
 
 470	if (ret)
 471		goto out_quota_unlock;
 472
 473	rblocks = RES_DINODE + ind_blocks;
 474	if (gfs2_is_jdata(ip))
 475		rblocks += data_blocks ? data_blocks : 1;
 476	if (ind_blocks || data_blocks) {
 477		rblocks += RES_STATFS + RES_QUOTA;
 478		rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
 479	}
 480	ret = gfs2_trans_begin(sdp, rblocks, 0);
 481	if (ret)
 482		goto out_trans_fail;
 483
 484	lock_page(page);
 485	ret = -EINVAL;
 486	size = i_size_read(inode);
 487	last_index = (size - 1) >> PAGE_SHIFT;
 488	/* Check page index against inode size */
 489	if (size == 0 || (page->index > last_index))
 490		goto out_trans_end;
 491
 492	ret = -EAGAIN;
 493	/* If truncated, we must retry the operation, we may have raced
 494	 * with the glock demotion code.
 495	 */
 496	if (!PageUptodate(page) || page->mapping != inode->i_mapping)
 497		goto out_trans_end;
 498
 499	/* Unstuff, if required, and allocate backing blocks for page */
 500	ret = 0;
 501	if (gfs2_is_stuffed(ip))
 
 
 502		ret = gfs2_unstuff_dinode(ip, page);
 503	if (ret == 0)
 504		ret = gfs2_allocate_page_backing(page);
 
 
 505
 506out_trans_end:
 507	if (ret)
 508		unlock_page(page);
 509	gfs2_trans_end(sdp);
 510out_trans_fail:
 511	gfs2_inplace_release(ip);
 512out_quota_unlock:
 513	gfs2_quota_unlock(ip);
 
 
 514out_unlock:
 515	gfs2_glock_dq(&gh);
 516out_uninit:
 517	gfs2_holder_uninit(&gh);
 518	if (ret == 0) {
 519		set_page_dirty(page);
 520		wait_for_stable_page(page);
 521	}
 522out:
 523	sb_end_pagefault(inode->i_sb);
 524	return block_page_mkwrite_return(ret);
 525}
 526
 527static const struct vm_operations_struct gfs2_vm_ops = {
 528	.fault = filemap_fault,
 529	.map_pages = filemap_map_pages,
 530	.page_mkwrite = gfs2_page_mkwrite,
 531};
 532
 533/**
 534 * gfs2_mmap -
 535 * @file: The file to map
 536 * @vma: The VMA which described the mapping
 537 *
 538 * There is no need to get a lock here unless we should be updating
 539 * atime. We ignore any locking errors since the only consequence is
 540 * a missed atime update (which will just be deferred until later).
 541 *
 542 * Returns: 0
 543 */
 544
 545static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
 546{
 547	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 548
 549	if (!(file->f_flags & O_NOATIME) &&
 550	    !IS_NOATIME(&ip->i_inode)) {
 551		struct gfs2_holder i_gh;
 552		int error;
 553
 554		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 555					   &i_gh);
 
 
 
 
 
 556		if (error)
 557			return error;
 558		/* grab lock to update inode */
 559		gfs2_glock_dq_uninit(&i_gh);
 560		file_accessed(file);
 561	}
 562	vma->vm_ops = &gfs2_vm_ops;
 
 563
 564	return 0;
 565}
 566
 567/**
 568 * gfs2_open_common - This is common to open and atomic_open
 569 * @inode: The inode being opened
 570 * @file: The file being opened
 571 *
 572 * This maybe called under a glock or not depending upon how it has
 573 * been called. We must always be called under a glock for regular
 574 * files, however. For other file types, it does not matter whether
 575 * we hold the glock or not.
 576 *
 577 * Returns: Error code or 0 for success
 578 */
 579
 580int gfs2_open_common(struct inode *inode, struct file *file)
 581{
 
 
 582	struct gfs2_file *fp;
 583	int ret;
 584
 585	if (S_ISREG(inode->i_mode)) {
 586		ret = generic_file_open(inode, file);
 587		if (ret)
 588			return ret;
 589	}
 590
 591	fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS);
 592	if (!fp)
 593		return -ENOMEM;
 594
 595	mutex_init(&fp->f_fl_mutex);
 596
 597	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
 598	file->private_data = fp;
 599	return 0;
 600}
 601
 602/**
 603 * gfs2_open - open a file
 604 * @inode: the inode to open
 605 * @file: the struct file for this opening
 606 *
 607 * After atomic_open, this function is only used for opening files
 608 * which are already cached. We must still get the glock for regular
 609 * files to ensure that we have the file size uptodate for the large
 610 * file check which is in the common code. That is only an issue for
 611 * regular files though.
 612 *
 613 * Returns: errno
 614 */
 615
 616static int gfs2_open(struct inode *inode, struct file *file)
 617{
 618	struct gfs2_inode *ip = GFS2_I(inode);
 619	struct gfs2_holder i_gh;
 620	int error;
 621	bool need_unlock = false;
 622
 623	if (S_ISREG(ip->i_inode.i_mode)) {
 624		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
 625					   &i_gh);
 626		if (error)
 627			return error;
 628		need_unlock = true;
 629	}
 630
 631	error = gfs2_open_common(inode, file);
 
 
 
 
 632
 633	if (need_unlock)
 634		gfs2_glock_dq_uninit(&i_gh);
 
 635
 
 
 
 
 
 
 
 636	return error;
 637}
 638
 639/**
 640 * gfs2_release - called to close a struct file
 641 * @inode: the inode the struct file belongs to
 642 * @file: the struct file being closed
 643 *
 644 * Returns: errno
 645 */
 646
 647static int gfs2_release(struct inode *inode, struct file *file)
 648{
 649	struct gfs2_inode *ip = GFS2_I(inode);
 
 650
 651	kfree(file->private_data);
 652	file->private_data = NULL;
 653
 654	if (!(file->f_mode & FMODE_WRITE))
 655		return 0;
 
 
 656
 657	gfs2_rsqa_delete(ip, &inode->i_writecount);
 658	return 0;
 659}
 660
 661/**
 662 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 663 * @file: the file that points to the dentry
 664 * @start: the start position in the file to sync
 665 * @end: the end position in the file to sync
 666 * @datasync: set if we can ignore timestamp changes
 667 *
 668 * We split the data flushing here so that we don't wait for the data
 669 * until after we've also sent the metadata to disk. Note that for
 670 * data=ordered, we will write & wait for the data at the log flush
 671 * stage anyway, so this is unlikely to make much of a difference
 672 * except in the data=writeback case.
 673 *
 674 * If the fdatawrite fails due to any reason except -EIO, we will
 675 * continue the remainder of the fsync, although we'll still report
 676 * the error at the end. This is to match filemap_write_and_wait_range()
 677 * behaviour.
 678 *
 679 * Returns: errno
 680 */
 681
 682static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 683		      int datasync)
 684{
 685	struct address_space *mapping = file->f_mapping;
 686	struct inode *inode = mapping->host;
 687	int sync_state = inode->i_state & I_DIRTY_ALL;
 688	struct gfs2_inode *ip = GFS2_I(inode);
 689	int ret = 0, ret1 = 0;
 690
 691	if (mapping->nrpages) {
 692		ret1 = filemap_fdatawrite_range(mapping, start, end);
 693		if (ret1 == -EIO)
 694			return ret1;
 695	}
 696
 697	if (!gfs2_is_jdata(ip))
 698		sync_state &= ~I_DIRTY_PAGES;
 699	if (datasync)
 700		sync_state &= ~(I_DIRTY_SYNC | I_DIRTY_TIME);
 701
 702	if (sync_state) {
 703		ret = sync_inode_metadata(inode, 1);
 704		if (ret)
 
 705			return ret;
 706		if (gfs2_is_jdata(ip))
 707			ret = file_write_and_wait(file);
 708		if (ret)
 709			return ret;
 710		gfs2_ail_flush(ip->i_gl, 1);
 711	}
 712
 713	if (mapping->nrpages)
 714		ret = file_fdatawait_range(file, start, end);
 715
 716	return ret ? ret : ret1;
 717}
 718
 719static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 720{
 721	struct file *file = iocb->ki_filp;
 722	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
 723	size_t count = iov_iter_count(to);
 724	struct gfs2_holder gh;
 725	ssize_t ret;
 726
 727	if (!count)
 728		return 0; /* skip atime */
 729
 730	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
 731	ret = gfs2_glock_nq(&gh);
 732	if (ret)
 733		goto out_uninit;
 734
 735	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL);
 736
 737	gfs2_glock_dq(&gh);
 738out_uninit:
 739	gfs2_holder_uninit(&gh);
 740	return ret;
 741}
 742
 743static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
 744{
 745	struct file *file = iocb->ki_filp;
 746	struct inode *inode = file->f_mapping->host;
 747	struct gfs2_inode *ip = GFS2_I(inode);
 748	size_t len = iov_iter_count(from);
 749	loff_t offset = iocb->ki_pos;
 750	struct gfs2_holder gh;
 751	ssize_t ret;
 752
 753	/*
 754	 * Deferred lock, even if its a write, since we do no allocation on
 755	 * this path. All we need to change is the atime, and this lock mode
 756	 * ensures that other nodes have flushed their buffered read caches
 757	 * (i.e. their page cache entries for this inode). We do not,
 758	 * unfortunately, have the option of only flushing a range like the
 759	 * VFS does.
 760	 */
 761	gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, &gh);
 762	ret = gfs2_glock_nq(&gh);
 763	if (ret)
 764		goto out_uninit;
 765
 766	/* Silently fall back to buffered I/O when writing beyond EOF */
 767	if (offset + len > i_size_read(&ip->i_inode))
 768		goto out;
 769
 770	ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL);
 771
 772out:
 773	gfs2_glock_dq(&gh);
 774out_uninit:
 775	gfs2_holder_uninit(&gh);
 776	return ret;
 777}
 778
 779static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 780{
 781	ssize_t ret;
 782
 783	if (iocb->ki_flags & IOCB_DIRECT) {
 784		ret = gfs2_file_direct_read(iocb, to);
 785		if (likely(ret != -ENOTBLK))
 786			return ret;
 787		iocb->ki_flags &= ~IOCB_DIRECT;
 788	}
 789	return generic_file_read_iter(iocb, to);
 790}
 791
 792/**
 793 * gfs2_file_write_iter - Perform a write to a file
 794 * @iocb: The io context
 795 * @from: The data to write
 
 
 796 *
 797 * We have to do a lock/unlock here to refresh the inode size for
 798 * O_APPEND writes, otherwise we can land up writing at the wrong
 799 * offset. There is still a race, but provided the app is using its
 800 * own file locking, this will make O_APPEND work as expected.
 801 *
 802 */
 803
 804static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 
 805{
 806	struct file *file = iocb->ki_filp;
 807	struct inode *inode = file_inode(file);
 808	struct gfs2_inode *ip = GFS2_I(inode);
 809	ssize_t written = 0, ret;
 810
 811	ret = gfs2_rsqa_alloc(ip);
 812	if (ret)
 813		return ret;
 814
 815	gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from));
 816
 817	if (iocb->ki_flags & IOCB_APPEND) {
 
 
 818		struct gfs2_holder gh;
 
 819
 820		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
 821		if (ret)
 822			return ret;
 823		gfs2_glock_dq_uninit(&gh);
 824	}
 825
 826	inode_lock(inode);
 827	ret = generic_write_checks(iocb, from);
 828	if (ret <= 0)
 829		goto out;
 830
 831	/* We can write back this queue in page reclaim */
 832	current->backing_dev_info = inode_to_bdi(inode);
 
 
 
 
 
 
 833
 834	ret = file_remove_privs(file);
 835	if (ret)
 836		goto out2;
 837
 838	ret = file_update_time(file);
 839	if (ret)
 840		goto out2;
 841
 842	if (iocb->ki_flags & IOCB_DIRECT) {
 843		struct address_space *mapping = file->f_mapping;
 844		loff_t pos, endbyte;
 845		ssize_t buffered;
 846
 847		written = gfs2_file_direct_write(iocb, from);
 848		if (written < 0 || !iov_iter_count(from))
 849			goto out2;
 850
 851		ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
 852		if (unlikely(ret < 0))
 853			goto out2;
 854		buffered = ret;
 
 
 
 
 
 
 
 
 855
 856		/*
 857		 * We need to ensure that the page cache pages are written to
 858		 * disk and invalidated to preserve the expected O_DIRECT
 859		 * semantics.
 860		 */
 861		pos = iocb->ki_pos;
 862		endbyte = pos + buffered - 1;
 863		ret = filemap_write_and_wait_range(mapping, pos, endbyte);
 864		if (!ret) {
 865			iocb->ki_pos += buffered;
 866			written += buffered;
 867			invalidate_mapping_pages(mapping,
 868						 pos >> PAGE_SHIFT,
 869						 endbyte >> PAGE_SHIFT);
 870		} else {
 871			/*
 872			 * We don't know how much we wrote, so just return
 873			 * the number of bytes which were direct-written
 874			 */
 875		}
 876	} else {
 877		ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
 878		if (likely(ret > 0))
 879			iocb->ki_pos += ret;
 880	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 881
 882out2:
 883	current->backing_dev_info = NULL;
 884out:
 885	inode_unlock(inode);
 886	if (likely(ret > 0)) {
 887		/* Handle various SYNC-type writes */
 888		ret = generic_write_sync(iocb, ret);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 889	}
 890	return written ? written : ret;
 
 891}
 892
 893static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
 894			   int mode)
 895{
 896	struct super_block *sb = inode->i_sb;
 897	struct gfs2_inode *ip = GFS2_I(inode);
 898	loff_t end = offset + len;
 899	struct buffer_head *dibh;
 900	int error;
 
 
 
 
 
 
 
 
 
 
 901
 902	error = gfs2_meta_inode_buffer(ip, &dibh);
 903	if (unlikely(error))
 904		return error;
 905
 906	gfs2_trans_add_meta(ip->i_gl, dibh);
 907
 908	if (gfs2_is_stuffed(ip)) {
 909		error = gfs2_unstuff_dinode(ip, NULL);
 910		if (unlikely(error))
 911			goto out;
 912	}
 913
 914	while (offset < end) {
 915		struct iomap iomap = { };
 
 
 
 
 
 
 
 
 
 916
 917		error = gfs2_iomap_get_alloc(inode, offset, end - offset,
 918					     &iomap);
 
 
 
 
 
 
 
 919		if (error)
 920			goto out;
 921		offset = iomap.offset + iomap.length;
 922		if (!(iomap.flags & IOMAP_F_NEW))
 923			continue;
 924		error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits,
 925					 iomap.length >> inode->i_blkbits,
 926					 GFP_NOFS);
 927		if (error) {
 928			fs_err(GFS2_SB(inode), "Failed to zero data buffers\n");
 929			goto out;
 930		}
 931	}
 
 
 
 
 
 
 932out:
 933	brelse(dibh);
 934	return error;
 935}
 936/**
 937 * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of
 938 *                     blocks, determine how many bytes can be written.
 939 * @ip:          The inode in question.
 940 * @len:         Max cap of bytes. What we return in *len must be <= this.
 941 * @data_blocks: Compute and return the number of data blocks needed
 942 * @ind_blocks:  Compute and return the number of indirect blocks needed
 943 * @max_blocks:  The total blocks available to work with.
 944 *
 945 * Returns: void, but @len, @data_blocks and @ind_blocks are filled in.
 946 */
 947static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len,
 948			    unsigned int *data_blocks, unsigned int *ind_blocks,
 949			    unsigned int max_blocks)
 950{
 951	loff_t max = *len;
 952	const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 
 953	unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
 954
 955	for (tmp = max_data; tmp > sdp->sd_diptrs;) {
 956		tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
 957		max_data -= tmp;
 958	}
 959
 
 
 
 960	*data_blocks = max_data;
 961	*ind_blocks = max_blocks - max_data;
 962	*len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
 963	if (*len > max) {
 964		*len = max;
 965		gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
 966	}
 967}
 968
 969static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 
 970{
 971	struct inode *inode = file_inode(file);
 972	struct gfs2_sbd *sdp = GFS2_SB(inode);
 973	struct gfs2_inode *ip = GFS2_I(inode);
 974	struct gfs2_alloc_parms ap = { .aflags = 0, };
 975	unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
 976	loff_t bytes, max_bytes, max_blks;
 
 977	int error;
 978	const loff_t pos = offset;
 979	const loff_t count = len;
 980	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
 981	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
 982	loff_t max_chunk_size = UINT_MAX & bsize_mask;
 983
 984	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
 
 
 985
 986	offset &= bsize_mask;
 987
 988	len = next - offset;
 989	bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
 990	if (!bytes)
 991		bytes = UINT_MAX;
 992	bytes &= bsize_mask;
 993	if (bytes == 0)
 994		bytes = sdp->sd_sb.sb_bsize;
 995
 996	gfs2_size_hint(file, offset, len);
 
 
 
 997
 998	gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
 999	ap.min_target = data_blocks + ind_blocks;
1000
1001	while (len > 0) {
1002		if (len < bytes)
1003			bytes = len;
1004		if (!gfs2_write_alloc_required(ip, offset, bytes)) {
1005			len -= bytes;
1006			offset += bytes;
1007			continue;
1008		}
1009
1010		/* We need to determine how many bytes we can actually
1011		 * fallocate without exceeding quota or going over the
1012		 * end of the fs. We start off optimistically by assuming
1013		 * we can write max_bytes */
1014		max_bytes = (len > max_chunk_size) ? max_chunk_size : len;
1015
1016		/* Since max_bytes is most likely a theoretical max, we
1017		 * calculate a more realistic 'bytes' to serve as a good
1018		 * starting point for the number of bytes we may be able
1019		 * to write */
1020		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
1021		ap.target = data_blocks + ind_blocks;
1022
1023		error = gfs2_quota_lock_check(ip, &ap);
1024		if (error)
1025			return error;
1026		/* ap.allowed tells us how many blocks quota will allow
1027		 * us to write. Check if this reduces max_blks */
1028		max_blks = UINT_MAX;
1029		if (ap.allowed)
1030			max_blks = ap.allowed;
1031
1032		error = gfs2_inplace_reserve(ip, &ap);
1033		if (error)
1034			goto out_qunlock;
1035
1036		/* check if the selected rgrp limits our max_blks further */
1037		if (ap.allowed && ap.allowed < max_blks)
1038			max_blks = ap.allowed;
1039
1040		/* Almost done. Calculate bytes that can be written using
1041		 * max_blks. We also recompute max_bytes, data_blocks and
1042		 * ind_blocks */
1043		calc_max_reserv(ip, &max_bytes, &data_blocks,
1044				&ind_blocks, max_blks);
1045
1046		rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
1047			  RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks);
1048		if (gfs2_is_jdata(ip))
1049			rblocks += data_blocks ? data_blocks : 1;
1050
1051		error = gfs2_trans_begin(sdp, rblocks,
1052					 PAGE_SIZE >> inode->i_blkbits);
1053		if (error)
1054			goto out_trans_fail;
1055
1056		error = fallocate_chunk(inode, offset, max_bytes, mode);
1057		gfs2_trans_end(sdp);
1058
1059		if (error)
1060			goto out_trans_fail;
1061
1062		len -= max_bytes;
1063		offset += max_bytes;
1064		gfs2_inplace_release(ip);
1065		gfs2_quota_unlock(ip);
 
1066	}
1067
1068	if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size)
1069		i_size_write(inode, pos + count);
1070	file_update_time(file);
1071	mark_inode_dirty(inode);
1072
1073	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
1074		return vfs_fsync_range(file, pos, pos + count - 1,
1075			       (file->f_flags & __O_SYNC) ? 0 : 1);
1076	return 0;
1077
1078out_trans_fail:
1079	gfs2_inplace_release(ip);
1080out_qunlock:
1081	gfs2_quota_unlock(ip);
 
 
 
 
 
 
1082	return error;
1083}
1084
1085static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
1086{
1087	struct inode *inode = file_inode(file);
1088	struct gfs2_sbd *sdp = GFS2_SB(inode);
1089	struct gfs2_inode *ip = GFS2_I(inode);
1090	struct gfs2_holder gh;
1091	int ret;
1092
1093	if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))
1094		return -EOPNOTSUPP;
1095	/* fallocate is needed by gfs2_grow to reserve space in the rindex */
1096	if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
1097		return -EOPNOTSUPP;
1098
1099	inode_lock(inode);
1100
1101	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
1102	ret = gfs2_glock_nq(&gh);
1103	if (ret)
1104		goto out_uninit;
1105
1106	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
1107	    (offset + len) > inode->i_size) {
1108		ret = inode_newsize_ok(inode, offset + len);
1109		if (ret)
1110			goto out_unlock;
1111	}
1112
1113	ret = get_write_access(inode);
1114	if (ret)
1115		goto out_unlock;
1116
1117	if (mode & FALLOC_FL_PUNCH_HOLE) {
1118		ret = __gfs2_punch_hole(file, offset, len);
1119	} else {
1120		ret = gfs2_rsqa_alloc(ip);
1121		if (ret)
1122			goto out_putw;
1123
1124		ret = __gfs2_fallocate(file, mode, offset, len);
1125
1126		if (ret)
1127			gfs2_rs_deltree(&ip->i_res);
1128	}
1129
1130out_putw:
1131	put_write_access(inode);
1132out_unlock:
1133	gfs2_glock_dq(&gh);
1134out_uninit:
1135	gfs2_holder_uninit(&gh);
1136	inode_unlock(inode);
1137	return ret;
1138}
1139
1140static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe,
1141				      struct file *out, loff_t *ppos,
1142				      size_t len, unsigned int flags)
1143{
1144	int error;
1145	struct gfs2_inode *ip = GFS2_I(out->f_mapping->host);
1146
1147	error = gfs2_rsqa_alloc(ip);
1148	if (error)
1149		return (ssize_t)error;
1150
1151	gfs2_size_hint(out, *ppos, len);
1152
1153	return iter_file_splice_write(pipe, out, ppos, len, flags);
1154}
1155
1156#ifdef CONFIG_GFS2_FS_LOCKING_DLM
1157
1158/**
1159 * gfs2_lock - acquire/release a posix lock on a file
1160 * @file: the file pointer
1161 * @cmd: either modify or retrieve lock state, possibly wait
1162 * @fl: type and range of lock
1163 *
1164 * Returns: errno
1165 */
1166
1167static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
1168{
1169	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
1170	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
1171	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
1172
1173	if (!(fl->fl_flags & FL_POSIX))
1174		return -ENOLCK;
1175	if (__mandatory_lock(&ip->i_inode) && fl->fl_type != F_UNLCK)
1176		return -ENOLCK;
1177
1178	if (cmd == F_CANCELLK) {
1179		/* Hack: */
1180		cmd = F_SETLK;
1181		fl->fl_type = F_UNLCK;
1182	}
1183	if (unlikely(test_bit(SDF_WITHDRAWN, &sdp->sd_flags))) {
1184		if (fl->fl_type == F_UNLCK)
1185			locks_lock_file_wait(file, fl);
1186		return -EIO;
1187	}
1188	if (IS_GETLK(cmd))
1189		return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
1190	else if (fl->fl_type == F_UNLCK)
1191		return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
1192	else
1193		return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
1194}
1195
1196static int do_flock(struct file *file, int cmd, struct file_lock *fl)
1197{
1198	struct gfs2_file *fp = file->private_data;
1199	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1200	struct gfs2_inode *ip = GFS2_I(file_inode(file));
1201	struct gfs2_glock *gl;
1202	unsigned int state;
1203	u16 flags;
1204	int error = 0;
1205	int sleeptime;
1206
1207	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
1208	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY_1CB) | GL_EXACT;
1209
1210	mutex_lock(&fp->f_fl_mutex);
1211
1212	if (gfs2_holder_initialized(fl_gh)) {
1213		struct file_lock request;
1214		if (fl_gh->gh_state == state)
1215			goto out;
1216		locks_init_lock(&request);
1217		request.fl_type = F_UNLCK;
1218		request.fl_flags = FL_FLOCK;
1219		locks_lock_file_wait(file, &request);
1220		gfs2_glock_dq(fl_gh);
1221		gfs2_holder_reinit(state, flags, fl_gh);
1222	} else {
1223		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
1224				       &gfs2_flock_glops, CREATE, &gl);
1225		if (error)
1226			goto out;
1227		gfs2_holder_init(gl, state, flags, fl_gh);
1228		gfs2_glock_put(gl);
1229	}
1230	for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) {
1231		error = gfs2_glock_nq(fl_gh);
1232		if (error != GLR_TRYFAILED)
1233			break;
1234		fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT;
1235		fl_gh->gh_error = 0;
1236		msleep(sleeptime);
1237	}
1238	if (error) {
1239		gfs2_holder_uninit(fl_gh);
1240		if (error == GLR_TRYFAILED)
1241			error = -EAGAIN;
1242	} else {
1243		error = locks_lock_file_wait(file, fl);
1244		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
1245	}
1246
1247out:
1248	mutex_unlock(&fp->f_fl_mutex);
1249	return error;
1250}
1251
1252static void do_unflock(struct file *file, struct file_lock *fl)
1253{
1254	struct gfs2_file *fp = file->private_data;
1255	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
1256
1257	mutex_lock(&fp->f_fl_mutex);
1258	locks_lock_file_wait(file, fl);
1259	if (gfs2_holder_initialized(fl_gh)) {
1260		gfs2_glock_dq(fl_gh);
1261		gfs2_holder_uninit(fl_gh);
1262	}
1263	mutex_unlock(&fp->f_fl_mutex);
1264}
1265
1266/**
1267 * gfs2_flock - acquire/release a flock lock on a file
1268 * @file: the file pointer
1269 * @cmd: either modify or retrieve lock state, possibly wait
1270 * @fl: type and range of lock
1271 *
1272 * Returns: errno
1273 */
1274
1275static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
1276{
1277	if (!(fl->fl_flags & FL_FLOCK))
1278		return -ENOLCK;
1279	if (fl->fl_type & LOCK_MAND)
1280		return -EOPNOTSUPP;
1281
1282	if (fl->fl_type == F_UNLCK) {
1283		do_unflock(file, fl);
1284		return 0;
1285	} else {
1286		return do_flock(file, cmd, fl);
1287	}
1288}
1289
1290const struct file_operations gfs2_file_fops = {
1291	.llseek		= gfs2_llseek,
1292	.read_iter	= gfs2_file_read_iter,
1293	.write_iter	= gfs2_file_write_iter,
1294	.iopoll		= iomap_dio_iopoll,
 
1295	.unlocked_ioctl	= gfs2_ioctl,
1296	.mmap		= gfs2_mmap,
1297	.open		= gfs2_open,
1298	.release	= gfs2_release,
1299	.fsync		= gfs2_fsync,
1300	.lock		= gfs2_lock,
1301	.flock		= gfs2_flock,
1302	.splice_read	= generic_file_splice_read,
1303	.splice_write	= gfs2_file_splice_write,
1304	.setlease	= simple_nosetlease,
1305	.fallocate	= gfs2_fallocate,
1306};
1307
1308const struct file_operations gfs2_dir_fops = {
1309	.iterate_shared	= gfs2_readdir,
1310	.unlocked_ioctl	= gfs2_ioctl,
1311	.open		= gfs2_open,
1312	.release	= gfs2_release,
1313	.fsync		= gfs2_fsync,
1314	.lock		= gfs2_lock,
1315	.flock		= gfs2_flock,
1316	.llseek		= default_llseek,
1317};
1318
1319#endif /* CONFIG_GFS2_FS_LOCKING_DLM */
1320
1321const struct file_operations gfs2_file_fops_nolock = {
1322	.llseek		= gfs2_llseek,
1323	.read_iter	= gfs2_file_read_iter,
1324	.write_iter	= gfs2_file_write_iter,
1325	.iopoll		= iomap_dio_iopoll,
 
1326	.unlocked_ioctl	= gfs2_ioctl,
1327	.mmap		= gfs2_mmap,
1328	.open		= gfs2_open,
1329	.release	= gfs2_release,
1330	.fsync		= gfs2_fsync,
1331	.splice_read	= generic_file_splice_read,
1332	.splice_write	= gfs2_file_splice_write,
1333	.setlease	= generic_setlease,
1334	.fallocate	= gfs2_fallocate,
1335};
1336
1337const struct file_operations gfs2_dir_fops_nolock = {
1338	.iterate_shared	= gfs2_readdir,
1339	.unlocked_ioctl	= gfs2_ioctl,
1340	.open		= gfs2_open,
1341	.release	= gfs2_release,
1342	.fsync		= gfs2_fsync,
1343	.llseek		= default_llseek,
1344};
1345