File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
new file mode 100644
index 0000000..41aa3ca
--- /dev/null
+++ b/fs/jfs/inode.c
@@ -0,0 +1,424 @@
+/*
+ *   Copyright (C) International Business Machines Corp., 2000-2004
+ *   Portions Copyright (C) Christoph Hellwig, 2001-2002
+ *
+ *   This program is free software;  you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program;  if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/fs.h>
+#include <linux/mpage.h>
+#include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/uio.h>
+#include <linux/writeback.h>
+#include "jfs_incore.h"
+#include "jfs_inode.h"
+#include "jfs_filsys.h"
+#include "jfs_imap.h"
+#include "jfs_extent.h"
+#include "jfs_unicode.h"
+#include "jfs_debug.h"
+
+
+struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
+{
+	struct inode *inode;
+	int ret;
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+
+	ret = diRead(inode);
+	if (ret < 0) {
+		iget_failed(inode);
+		return ERR_PTR(ret);
+	}
+
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &jfs_file_inode_operations;
+		inode->i_fop = &jfs_file_operations;
+		inode->i_mapping->a_ops = &jfs_aops;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &jfs_dir_inode_operations;
+		inode->i_fop = &jfs_dir_operations;
+	} else if (S_ISLNK(inode->i_mode)) {
+		if (inode->i_size >= IDATASIZE) {
+			inode->i_op = &page_symlink_inode_operations;
+			inode->i_mapping->a_ops = &jfs_aops;
+		} else {
+			inode->i_op = &jfs_fast_symlink_inode_operations;
+			inode->i_link = JFS_IP(inode)->i_inline;
+			/*
+			 * The inline data should be null-terminated, but
+			 * don't let on-disk corruption crash the kernel
+			 */
+			inode->i_link[inode->i_size] = '\0';
+		}
+	} else {
+		inode->i_op = &jfs_file_inode_operations;
+		init_special_inode(inode, inode->i_mode, inode->i_rdev);
+	}
+	unlock_new_inode(inode);
+	return inode;
+}
+
+/*
+ * Workhorse of both fsync & write_inode
+ */
+int jfs_commit_inode(struct inode *inode, int wait)
+{
+	int rc = 0;
+	tid_t tid;
+	static int noisy = 5;
+
+	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
+
+	/*
+	 * Don't commit if inode has been committed since last being
+	 * marked dirty, or if it has been deleted.
+	 */
+	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
+		return 0;
+
+	if (isReadOnly(inode)) {
+		/* kernel allows writes to devices on read-only
+		 * partitions and may think inode is dirty
+		 */
+		if (!special_file(inode->i_mode) && noisy) {
+			jfs_err("jfs_commit_inode(0x%p) called on "
+				   "read-only volume", inode);
+			jfs_err("Is remount racy?");
+			noisy--;
+		}
+		return 0;
+	}
+
+	tid = txBegin(inode->i_sb, COMMIT_INODE);
+	mutex_lock(&JFS_IP(inode)->commit_mutex);
+
+	/*
+	 * Retest inode state after taking commit_mutex
+	 */
+	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
+		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
+
+	txEnd(tid);
+	mutex_unlock(&JFS_IP(inode)->commit_mutex);
+	return rc;
+}
+
+int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int wait = wbc->sync_mode == WB_SYNC_ALL;
+
+	if (inode->i_nlink == 0)
+		return 0;
+	/*
+	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
+	 * It has been committed since the last change, but was still
+	 * on the dirty inode list.
+	 */
+	if (!test_cflag(COMMIT_Dirty, inode)) {
+		/* Make sure committed changes hit the disk */
+		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
+		return 0;
+	}
+
+	if (jfs_commit_inode(inode, wait)) {
+		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
+		return -EIO;
+	} else
+		return 0;
+}
+
+void jfs_evict_inode(struct inode *inode)
+{
+	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
+
+	if (!inode->i_nlink && !is_bad_inode(inode)) {
+		dquot_initialize(inode);
+
+		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
+			truncate_inode_pages_final(&inode->i_data);
+
+			if (test_cflag(COMMIT_Freewmap, inode))
+				jfs_free_zero_link(inode);
+
+			diFree(inode);
+
+			/*
+			 * Free the inode from the quota allocation.
+			 */
+			dquot_initialize(inode);
+			dquot_free_inode(inode);
+		}
+	} else {
+		truncate_inode_pages_final(&inode->i_data);
+	}
+	clear_inode(inode);
+	dquot_drop(inode);
+}
+
+void jfs_dirty_inode(struct inode *inode, int flags)
+{
+	static int noisy = 5;
+
+	if (isReadOnly(inode)) {
+		if (!special_file(inode->i_mode) && noisy) {
+			/* kernel allows writes to devices on read-only
+			 * partitions and may try to mark inode dirty
+			 */
+			jfs_err("jfs_dirty_inode called on read-only volume");
+			jfs_err("Is remount racy?");
+			noisy--;
+		}
+		return;
+	}
+
+	set_cflag(COMMIT_Dirty, inode);
+}
+
+int jfs_get_block(struct inode *ip, sector_t lblock,
+		  struct buffer_head *bh_result, int create)
+{
+	s64 lblock64 = lblock;
+	int rc = 0;
+	xad_t xad;
+	s64 xaddr;
+	int xflag;
+	s32 xlen = bh_result->b_size >> ip->i_blkbits;
+
+	/*
+	 * Take appropriate lock on inode
+	 */
+	if (create)
+		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
+	else
+		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
+
+	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
+	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
+	    xaddr) {
+		if (xflag & XAD_NOTRECORDED) {
+			if (!create)
+				/*
+				 * Allocated but not recorded, read treats
+				 * this as a hole
+				 */
+				goto unlock;
+#ifdef _JFS_4K
+			XADoffset(&xad, lblock64);
+			XADlength(&xad, xlen);
+			XADaddress(&xad, xaddr);
+#else				/* _JFS_4K */
+			/*
+			 * As long as block size = 4K, this isn't a problem.
+			 * We should mark the whole page not ABNR, but how
+			 * will we know to mark the other blocks BH_New?
+			 */
+			BUG();
+#endif				/* _JFS_4K */
+			rc = extRecord(ip, &xad);
+			if (rc)
+				goto unlock;
+			set_buffer_new(bh_result);
+		}
+
+		map_bh(bh_result, ip->i_sb, xaddr);
+		bh_result->b_size = xlen << ip->i_blkbits;
+		goto unlock;
+	}
+	if (!create)
+		goto unlock;
+
+	/*
+	 * Allocate a new block
+	 */
+#ifdef _JFS_4K
+	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
+		goto unlock;
+	rc = extAlloc(ip, xlen, lblock64, &xad, false);
+	if (rc)
+		goto unlock;
+
+	set_buffer_new(bh_result);
+	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
+	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
+
+#else				/* _JFS_4K */
+	/*
+	 * We need to do whatever it takes to keep all but the last buffers
+	 * in 4K pages - see jfs_write.c
+	 */
+	BUG();
+#endif				/* _JFS_4K */
+
+      unlock:
+	/*
+	 * Release lock on inode
+	 */
+	if (create)
+		IWRITE_UNLOCK(ip);
+	else
+		IREAD_UNLOCK(ip);
+	return rc;
+}
+
+static int jfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+	return block_write_full_page(page, jfs_get_block, wbc);
+}
+
+static int jfs_writepages(struct address_space *mapping,
+			struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, jfs_get_block);
+}
+
+static int jfs_readpage(struct file *file, struct page *page)
+{
+	return mpage_readpage(page, jfs_get_block);
+}
+
+static int jfs_readpages(struct file *file, struct address_space *mapping,
+		struct list_head *pages, unsigned nr_pages)
+{
+	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
+}
+
+static void jfs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size) {
+		truncate_pagecache(inode, inode->i_size);
+		jfs_truncate(inode);
+	}
+}
+
+static int jfs_write_begin(struct file *file, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata)
+{
+	int ret;
+
+	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
+				jfs_get_block);
+	if (unlikely(ret))
+		jfs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, jfs_get_block);
+}
+
+static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+			     loff_t offset)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = file->f_mapping->host;
+	size_t count = iov_iter_count(iter);
+	ssize_t ret;
+
+	ret = blockdev_direct_IO(iocb, inode, iter, offset, jfs_get_block);
+
+	/*
+	 * In case of error extending write may have instantiated a few
+	 * blocks outside i_size. Trim these off again.
+	 */
+	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
+		loff_t isize = i_size_read(inode);
+		loff_t end = offset + count;
+
+		if (end > isize)
+			jfs_write_failed(mapping, end);
+	}
+
+	return ret;
+}
+
+const struct address_space_operations jfs_aops = {
+	.readpage	= jfs_readpage,
+	.readpages	= jfs_readpages,
+	.writepage	= jfs_writepage,
+	.writepages	= jfs_writepages,
+	.write_begin	= jfs_write_begin,
+	.write_end	= nobh_write_end,
+	.bmap		= jfs_bmap,
+	.direct_IO	= jfs_direct_IO,
+};
+
+/*
+ * Guts of jfs_truncate.  Called with locks already held.  Can be called
+ * with directory for truncating directory index table.
+ */
+void jfs_truncate_nolock(struct inode *ip, loff_t length)
+{
+	loff_t newsize;
+	tid_t tid;
+
+	ASSERT(length >= 0);
+
+	if (test_cflag(COMMIT_Nolink, ip)) {
+		xtTruncate(0, ip, length, COMMIT_WMAP);
+		return;
+	}
+
+	do {
+		tid = txBegin(ip->i_sb, 0);
+
+		/*
+		 * The commit_mutex cannot be taken before txBegin.
+		 * txBegin may block and there is a chance the inode
+		 * could be marked dirty and need to be committed
+		 * before txBegin unblocks
+		 */
+		mutex_lock(&JFS_IP(ip)->commit_mutex);
+
+		newsize = xtTruncate(tid, ip, length,
+				     COMMIT_TRUNCATE | COMMIT_PWMAP);
+		if (newsize < 0) {
+			txEnd(tid);
+			mutex_unlock(&JFS_IP(ip)->commit_mutex);
+			break;
+		}
+
+		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
+		mark_inode_dirty(ip);
+
+		txCommit(tid, 1, &ip, 0);
+		txEnd(tid);
+		mutex_unlock(&JFS_IP(ip)->commit_mutex);
+	} while (newsize > length);	/* Truncate isn't always atomic */
+}
+
+void jfs_truncate(struct inode *ip)
+{
+	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
+
+	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
+
+	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
+	jfs_truncate_nolock(ip, ip->i_size);
+	IWRITE_UNLOCK(ip);
+}