xfs_file.c 36.5 KB
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/*
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 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
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 *
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 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
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 * published by the Free Software Foundation.
 *
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 * This program is distributed in the hope that it would 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.
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 *
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 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_shared.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
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#include "xfs_sb.h"
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#include "xfs_ag.h"
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#include "xfs_mount.h"
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#include "xfs_da_format.h"
#include "xfs_da_btree.h"
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#include "xfs_inode.h"
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#include "xfs_trans.h"
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#include "xfs_inode_item.h"
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#include "xfs_bmap.h"
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#include "xfs_bmap_util.h"
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#include "xfs_error.h"
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#include "xfs_dir2.h"
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#include "xfs_dir2_priv.h"
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#include "xfs_ioctl.h"
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#include "xfs_trace.h"
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#include "xfs_log.h"
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#include "xfs_dinode.h"
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#include <linux/aio.h>
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#include <linux/dcache.h>
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#include <linux/falloc.h>
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#include <linux/pagevec.h>
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static const struct vm_operations_struct xfs_file_vm_ops;
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/*
 * Locking primitives for read and write IO paths to ensure we consistently use
 * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
 */
static inline void
xfs_rw_ilock(
	struct xfs_inode	*ip,
	int			type)
{
	if (type & XFS_IOLOCK_EXCL)
		mutex_lock(&VFS_I(ip)->i_mutex);
	xfs_ilock(ip, type);
}

static inline void
xfs_rw_iunlock(
	struct xfs_inode	*ip,
	int			type)
{
	xfs_iunlock(ip, type);
	if (type & XFS_IOLOCK_EXCL)
		mutex_unlock(&VFS_I(ip)->i_mutex);
}

static inline void
xfs_rw_ilock_demote(
	struct xfs_inode	*ip,
	int			type)
{
	xfs_ilock_demote(ip, type);
	if (type & XFS_IOLOCK_EXCL)
		mutex_unlock(&VFS_I(ip)->i_mutex);
}

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/*
 *	xfs_iozero
 *
 *	xfs_iozero clears the specified range of buffer supplied,
 *	and marks all the affected blocks as valid and modified.  If
 *	an affected block is not allocated, it will be allocated.  If
 *	an affected block is not completely overwritten, and is not
 *	valid before the operation, it will be read from disk before
 *	being partially zeroed.
 */
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int
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xfs_iozero(
	struct xfs_inode	*ip,	/* inode			*/
	loff_t			pos,	/* offset in file		*/
	size_t			count)	/* size of data to zero		*/
{
	struct page		*page;
	struct address_space	*mapping;
	int			status;

	mapping = VFS_I(ip)->i_mapping;
	do {
		unsigned offset, bytes;
		void *fsdata;

		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
		bytes = PAGE_CACHE_SIZE - offset;
		if (bytes > count)
			bytes = count;

		status = pagecache_write_begin(NULL, mapping, pos, bytes,
					AOP_FLAG_UNINTERRUPTIBLE,
					&page, &fsdata);
		if (status)
			break;

		zero_user(page, offset, bytes);

		status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
					page, fsdata);
		WARN_ON(status <= 0); /* can't return less than zero! */
		pos += bytes;
		count -= bytes;
		status = 0;
	} while (count);

	return (-status);
}

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/*
 * Fsync operations on directories are much simpler than on regular files,
 * as there is no file data to flush, and thus also no need for explicit
 * cache flush operations, and there are no non-transaction metadata updates
 * on directories either.
 */
STATIC int
xfs_dir_fsync(
	struct file		*file,
	loff_t			start,
	loff_t			end,
	int			datasync)
{
	struct xfs_inode	*ip = XFS_I(file->f_mapping->host);
	struct xfs_mount	*mp = ip->i_mount;
	xfs_lsn_t		lsn = 0;

	trace_xfs_dir_fsync(ip);

	xfs_ilock(ip, XFS_ILOCK_SHARED);
	if (xfs_ipincount(ip))
		lsn = ip->i_itemp->ili_last_lsn;
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	if (!lsn)
		return 0;
	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
}

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STATIC int
xfs_file_fsync(
	struct file		*file,
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	loff_t			start,
	loff_t			end,
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	int			datasync)
{
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	struct inode		*inode = file->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
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	struct xfs_mount	*mp = ip->i_mount;
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	int			error = 0;
	int			log_flushed = 0;
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	xfs_lsn_t		lsn = 0;
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	trace_xfs_file_fsync(ip);
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	error = filemap_write_and_wait_range(inode->i_mapping, start, end);
	if (error)
		return error;

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	if (XFS_FORCED_SHUTDOWN(mp))
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		return -XFS_ERROR(EIO);

	xfs_iflags_clear(ip, XFS_ITRUNCATED);

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	if (mp->m_flags & XFS_MOUNT_BARRIER) {
		/*
		 * If we have an RT and/or log subvolume we need to make sure
		 * to flush the write cache the device used for file data
		 * first.  This is to ensure newly written file data make
		 * it to disk before logging the new inode size in case of
		 * an extending write.
		 */
		if (XFS_IS_REALTIME_INODE(ip))
			xfs_blkdev_issue_flush(mp->m_rtdev_targp);
		else if (mp->m_logdev_targp != mp->m_ddev_targp)
			xfs_blkdev_issue_flush(mp->m_ddev_targp);
	}

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	/*
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	 * All metadata updates are logged, which means that we just have
	 * to flush the log up to the latest LSN that touched the inode.
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	 */
	xfs_ilock(ip, XFS_ILOCK_SHARED);
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	if (xfs_ipincount(ip)) {
		if (!datasync ||
		    (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
			lsn = ip->i_itemp->ili_last_lsn;
	}
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	xfs_iunlock(ip, XFS_ILOCK_SHARED);
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	if (lsn)
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		error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);

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	/*
	 * If we only have a single device, and the log force about was
	 * a no-op we might have to flush the data device cache here.
	 * This can only happen for fdatasync/O_DSYNC if we were overwriting
	 * an already allocated file and thus do not have any metadata to
	 * commit.
	 */
	if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
	    mp->m_logdev_targp == mp->m_ddev_targp &&
	    !XFS_IS_REALTIME_INODE(ip) &&
	    !log_flushed)
		xfs_blkdev_issue_flush(mp->m_ddev_targp);
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	return -error;
}

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STATIC ssize_t
xfs_file_aio_read(
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	struct kiocb		*iocb,
	const struct iovec	*iovp,
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	unsigned long		nr_segs,
	loff_t			pos)
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{
	struct file		*file = iocb->ki_filp;
	struct inode		*inode = file->f_mapping->host;
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	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
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	size_t			size = 0;
	ssize_t			ret = 0;
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	int			ioflags = 0;
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	xfs_fsize_t		n;

	XFS_STATS_INC(xs_read_calls);

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	BUG_ON(iocb->ki_pos != pos);

	if (unlikely(file->f_flags & O_DIRECT))
		ioflags |= IO_ISDIRECT;
	if (file->f_mode & FMODE_NOCMTIME)
		ioflags |= IO_INVIS;

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	ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
	if (ret < 0)
		return ret;
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	if (unlikely(ioflags & IO_ISDIRECT)) {
		xfs_buftarg_t	*target =
			XFS_IS_REALTIME_INODE(ip) ?
				mp->m_rtdev_targp : mp->m_ddev_targp;
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		if ((pos | size) & target->bt_meta_sectormask) {
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			if (pos == i_size_read(inode))
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				return 0;
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			return -XFS_ERROR(EINVAL);
		}
	}

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	n = mp->m_super->s_maxbytes - pos;
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	if (n <= 0 || size == 0)
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		return 0;

	if (n < size)
		size = n;

	if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;

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	/*
	 * Locking is a bit tricky here. If we take an exclusive lock
	 * for direct IO, we effectively serialise all new concurrent
	 * read IO to this file and block it behind IO that is currently in
	 * progress because IO in progress holds the IO lock shared. We only
	 * need to hold the lock exclusive to blow away the page cache, so
	 * only take lock exclusively if the page cache needs invalidation.
	 * This allows the normal direct IO case of no page cache pages to
	 * proceeed concurrently without serialisation.
	 */
	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
	if ((ioflags & IO_ISDIRECT) && inode->i_mapping->nrpages) {
		xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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		xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);

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		if (inode->i_mapping->nrpages) {
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			ret = -filemap_write_and_wait_range(
							VFS_I(ip)->i_mapping,
							pos, -1);
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			if (ret) {
				xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
				return ret;
			}
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			truncate_pagecache_range(VFS_I(ip), pos, -1);
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		}
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		xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
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	}
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	trace_xfs_file_read(ip, size, pos, ioflags);
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	ret = generic_file_aio_read(iocb, iovp, nr_segs, pos);
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	if (ret > 0)
		XFS_STATS_ADD(xs_read_bytes, ret);

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	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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	return ret;
}

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STATIC ssize_t
xfs_file_splice_read(
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	struct file		*infilp,
	loff_t			*ppos,
	struct pipe_inode_info	*pipe,
	size_t			count,
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	unsigned int		flags)
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{
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	struct xfs_inode	*ip = XFS_I(infilp->f_mapping->host);
	int			ioflags = 0;
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	ssize_t			ret;

	XFS_STATS_INC(xs_read_calls);
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	if (infilp->f_mode & FMODE_NOCMTIME)
		ioflags |= IO_INVIS;

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	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
		return -EIO;

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	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
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	trace_xfs_file_splice_read(ip, count, *ppos, ioflags);

	ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
	if (ret > 0)
		XFS_STATS_ADD(xs_read_bytes, ret);

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	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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	return ret;
}

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/*
 * xfs_file_splice_write() does not use xfs_rw_ilock() because
 * generic_file_splice_write() takes the i_mutex itself. This, in theory,
 * couuld cause lock inversions between the aio_write path and the splice path
 * if someone is doing concurrent splice(2) based writes and write(2) based
 * writes to the same inode. The only real way to fix this is to re-implement
 * the generic code here with correct locking orders.
 */
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STATIC ssize_t
xfs_file_splice_write(
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	struct pipe_inode_info	*pipe,
	struct file		*outfilp,
	loff_t			*ppos,
	size_t			count,
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	unsigned int		flags)
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{
	struct inode		*inode = outfilp->f_mapping->host;
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	struct xfs_inode	*ip = XFS_I(inode);
	int			ioflags = 0;
	ssize_t			ret;
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	XFS_STATS_INC(xs_write_calls);
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	if (outfilp->f_mode & FMODE_NOCMTIME)
		ioflags |= IO_INVIS;

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	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
		return -EIO;

	xfs_ilock(ip, XFS_IOLOCK_EXCL);

	trace_xfs_file_splice_write(ip, count, *ppos, ioflags);

	ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
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	if (ret > 0)
		XFS_STATS_ADD(xs_write_bytes, ret);
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	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
	return ret;
}

/*
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 * This routine is called to handle zeroing any space in the last block of the
 * file that is beyond the EOF.  We do this since the size is being increased
 * without writing anything to that block and we don't want to read the
 * garbage on the disk.
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 */
STATIC int				/* error (positive) */
xfs_zero_last_block(
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	struct xfs_inode	*ip,
	xfs_fsize_t		offset,
	xfs_fsize_t		isize)
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{
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	struct xfs_mount	*mp = ip->i_mount;
	xfs_fileoff_t		last_fsb = XFS_B_TO_FSBT(mp, isize);
	int			zero_offset = XFS_B_FSB_OFFSET(mp, isize);
	int			zero_len;
	int			nimaps = 1;
	int			error = 0;
	struct xfs_bmbt_irec	imap;
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	xfs_ilock(ip, XFS_ILOCK_EXCL);
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	error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
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	xfs_iunlock(ip, XFS_ILOCK_EXCL);
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	if (error)
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		return error;
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	ASSERT(nimaps > 0);
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	/*
	 * If the block underlying isize is just a hole, then there
	 * is nothing to zero.
	 */
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	if (imap.br_startblock == HOLESTARTBLOCK)
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		return 0;

	zero_len = mp->m_sb.sb_blocksize - zero_offset;
	if (isize + zero_len > offset)
		zero_len = offset - isize;
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	return xfs_iozero(ip, isize, zero_len);
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}

/*
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 * Zero any on disk space between the current EOF and the new, larger EOF.
 *
 * This handles the normal case of zeroing the remainder of the last block in
 * the file and the unusual case of zeroing blocks out beyond the size of the
 * file.  This second case only happens with fixed size extents and when the
 * system crashes before the inode size was updated but after blocks were
 * allocated.
 *
 * Expects the iolock to be held exclusive, and will take the ilock internally.
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 */
int					/* error (positive) */
xfs_zero_eof(
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	struct xfs_inode	*ip,
	xfs_off_t		offset,		/* starting I/O offset */
	xfs_fsize_t		isize)		/* current inode size */
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{
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	struct xfs_mount	*mp = ip->i_mount;
	xfs_fileoff_t		start_zero_fsb;
	xfs_fileoff_t		end_zero_fsb;
	xfs_fileoff_t		zero_count_fsb;
	xfs_fileoff_t		last_fsb;
	xfs_fileoff_t		zero_off;
	xfs_fsize_t		zero_len;
	int			nimaps;
	int			error = 0;
	struct xfs_bmbt_irec	imap;

	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
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	ASSERT(offset > isize);

	/*
	 * First handle zeroing the block on which isize resides.
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	 *
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	 * We only zero a part of that block so it is handled specially.
	 */
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	if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
		error = xfs_zero_last_block(ip, offset, isize);
		if (error)
			return error;
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	}

	/*
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	 * Calculate the range between the new size and the old where blocks
	 * needing to be zeroed may exist.
	 *
	 * To get the block where the last byte in the file currently resides,
	 * we need to subtract one from the size and truncate back to a block
	 * boundary.  We subtract 1 in case the size is exactly on a block
	 * boundary.
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	 */
	last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
	start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
	end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
	ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
	if (last_fsb == end_zero_fsb) {
		/*
		 * The size was only incremented on its last block.
		 * We took care of that above, so just return.
		 */
		return 0;
	}

	ASSERT(start_zero_fsb <= end_zero_fsb);
	while (start_zero_fsb <= end_zero_fsb) {
		nimaps = 1;
		zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
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		xfs_ilock(ip, XFS_ILOCK_EXCL);
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		error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
					  &imap, &nimaps, 0);
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		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		if (error)
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			return error;
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		ASSERT(nimaps > 0);

		if (imap.br_state == XFS_EXT_UNWRITTEN ||
		    imap.br_startblock == HOLESTARTBLOCK) {
			start_zero_fsb = imap.br_startoff + imap.br_blockcount;
			ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
			continue;
		}

		/*
		 * There are blocks we need to zero.
		 */
		zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
		zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);

		if ((zero_off + zero_len) > offset)
			zero_len = offset - zero_off;

		error = xfs_iozero(ip, zero_off, zero_len);
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		if (error)
			return error;
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		start_zero_fsb = imap.br_startoff + imap.br_blockcount;
		ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
	}

	return 0;
}

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/*
 * Common pre-write limit and setup checks.
 *
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 * Called with the iolocked held either shared and exclusive according to
 * @iolock, and returns with it held.  Might upgrade the iolock to exclusive
 * if called for a direct write beyond i_size.
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 */
STATIC ssize_t
xfs_file_aio_write_checks(
	struct file		*file,
	loff_t			*pos,
	size_t			*count,
	int			*iolock)
{
	struct inode		*inode = file->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	int			error = 0;

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restart:
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	error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
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	if (error)
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		return error;

	/*
	 * If the offset is beyond the size of the file, we need to zero any
	 * blocks that fall between the existing EOF and the start of this
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	 * write.  If zeroing is needed and we are currently holding the
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	 * iolock shared, we need to update it to exclusive which implies
	 * having to redo all checks before.
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	 */
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	if (*pos > i_size_read(inode)) {
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		if (*iolock == XFS_IOLOCK_SHARED) {
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			xfs_rw_iunlock(ip, *iolock);
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			*iolock = XFS_IOLOCK_EXCL;
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			xfs_rw_ilock(ip, *iolock);
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			goto restart;
		}
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		error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
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		if (error)
			return error;
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	}
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	/*
	 * Updating the timestamps will grab the ilock again from
	 * xfs_fs_dirty_inode, so we have to call it after dropping the
	 * lock above.  Eventually we should look into a way to avoid
	 * the pointless lock roundtrip.
	 */
585 586 587 588 589
	if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
		error = file_update_time(file);
		if (error)
			return error;
	}
C
Christoph Hellwig 已提交
590

591 592 593 594 595 596 597 598
	/*
	 * If we're writing the file then make sure to clear the setuid and
	 * setgid bits if the process is not being run by root.  This keeps
	 * people from modifying setuid and setgid binaries.
	 */
	return file_remove_suid(file);
}

599 600 601 602
/*
 * xfs_file_dio_aio_write - handle direct IO writes
 *
 * Lock the inode appropriately to prepare for and issue a direct IO write.
603
 * By separating it from the buffered write path we remove all the tricky to
604 605
 * follow locking changes and looping.
 *
606 607 608 609 610 611 612 613 614 615 616 617 618
 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
 * pages are flushed out.
 *
 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
 * allowing them to be done in parallel with reads and other direct IO writes.
 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
 * needs to do sub-block zeroing and that requires serialisation against other
 * direct IOs to the same block. In this case we need to serialise the
 * submission of the unaligned IOs so that we don't get racing block zeroing in
 * the dio layer.  To avoid the problem with aio, we also need to wait for
 * outstanding IOs to complete so that unwritten extent conversion is completed
 * before we try to map the overlapping block. This is currently implemented by
C
Christoph Hellwig 已提交
619
 * hitting it with a big hammer (i.e. inode_dio_wait()).
620
 *
621 622 623 624 625 626 627 628 629
 * Returns with locks held indicated by @iolock and errors indicated by
 * negative return values.
 */
STATIC ssize_t
xfs_file_dio_aio_write(
	struct kiocb		*iocb,
	const struct iovec	*iovp,
	unsigned long		nr_segs,
	loff_t			pos,
630
	size_t			ocount)
631 632 633 634 635 636 637 638
{
	struct file		*file = iocb->ki_filp;
	struct address_space	*mapping = file->f_mapping;
	struct inode		*inode = mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	ssize_t			ret = 0;
	size_t			count = ocount;
639
	int			unaligned_io = 0;
640
	int			iolock;
641 642 643
	struct xfs_buftarg	*target = XFS_IS_REALTIME_INODE(ip) ?
					mp->m_rtdev_targp : mp->m_ddev_targp;

644
	if ((pos | count) & target->bt_meta_sectormask)
645 646
		return -XFS_ERROR(EINVAL);

647 648 649
	if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
		unaligned_io = 1;

650 651 652 653 654 655 656 657
	/*
	 * We don't need to take an exclusive lock unless there page cache needs
	 * to be invalidated or unaligned IO is being executed. We don't need to
	 * consider the EOF extension case here because
	 * xfs_file_aio_write_checks() will relock the inode as necessary for
	 * EOF zeroing cases and fill out the new inode size as appropriate.
	 */
	if (unaligned_io || mapping->nrpages)
658
		iolock = XFS_IOLOCK_EXCL;
659
	else
660 661
		iolock = XFS_IOLOCK_SHARED;
	xfs_rw_ilock(ip, iolock);
662 663 664 665 666 667

	/*
	 * Recheck if there are cached pages that need invalidate after we got
	 * the iolock to protect against other threads adding new pages while
	 * we were waiting for the iolock.
	 */
668 669 670 671
	if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
		xfs_rw_iunlock(ip, iolock);
		iolock = XFS_IOLOCK_EXCL;
		xfs_rw_ilock(ip, iolock);
672
	}
673

674
	ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
675
	if (ret)
676
		goto out;
677 678

	if (mapping->nrpages) {
D
Dave Chinner 已提交
679 680
		ret = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
						    pos, -1);
681
		if (ret)
682
			goto out;
D
Dave Chinner 已提交
683
		truncate_pagecache_range(VFS_I(ip), pos, -1);
684 685
	}

686 687 688 689 690
	/*
	 * If we are doing unaligned IO, wait for all other IO to drain,
	 * otherwise demote the lock if we had to flush cached pages
	 */
	if (unaligned_io)
C
Christoph Hellwig 已提交
691
		inode_dio_wait(inode);
692
	else if (iolock == XFS_IOLOCK_EXCL) {
693
		xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
694
		iolock = XFS_IOLOCK_SHARED;
695 696 697 698 699 700
	}

	trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
	ret = generic_file_direct_write(iocb, iovp,
			&nr_segs, pos, &iocb->ki_pos, count, ocount);

701 702 703
out:
	xfs_rw_iunlock(ip, iolock);

704 705 706 707 708
	/* No fallback to buffered IO on errors for XFS. */
	ASSERT(ret < 0 || ret == count);
	return ret;
}

709
STATIC ssize_t
710
xfs_file_buffered_aio_write(
711 712
	struct kiocb		*iocb,
	const struct iovec	*iovp,
713
	unsigned long		nr_segs,
714
	loff_t			pos,
715
	size_t			ocount)
716 717 718 719
{
	struct file		*file = iocb->ki_filp;
	struct address_space	*mapping = file->f_mapping;
	struct inode		*inode = mapping->host;
720
	struct xfs_inode	*ip = XFS_I(inode);
721 722
	ssize_t			ret;
	int			enospc = 0;
723
	int			iolock = XFS_IOLOCK_EXCL;
724
	size_t			count = ocount;
725

726
	xfs_rw_ilock(ip, iolock);
727

728
	ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
729
	if (ret)
730
		goto out;
731 732 733 734 735

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = mapping->backing_dev_info;

write_retry:
736 737
	trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
	ret = generic_file_buffered_write(iocb, iovp, nr_segs,
D
Dave Chinner 已提交
738 739
			pos, &iocb->ki_pos, count, 0);

740
	/*
D
Dave Chinner 已提交
741 742 743
	 * If we just got an ENOSPC, try to write back all dirty inodes to
	 * convert delalloc space to free up some of the excess reserved
	 * metadata space.
744 745 746
	 */
	if (ret == -ENOSPC && !enospc) {
		enospc = 1;
D
Dave Chinner 已提交
747 748
		xfs_flush_inodes(ip->i_mount);
		goto write_retry;
749
	}
750

751
	current->backing_dev_info = NULL;
752 753
out:
	xfs_rw_iunlock(ip, iolock);
754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781
	return ret;
}

STATIC ssize_t
xfs_file_aio_write(
	struct kiocb		*iocb,
	const struct iovec	*iovp,
	unsigned long		nr_segs,
	loff_t			pos)
{
	struct file		*file = iocb->ki_filp;
	struct address_space	*mapping = file->f_mapping;
	struct inode		*inode = mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	ssize_t			ret;
	size_t			ocount = 0;

	XFS_STATS_INC(xs_write_calls);

	BUG_ON(iocb->ki_pos != pos);

	ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
	if (ret)
		return ret;

	if (ocount == 0)
		return 0;

J
Jan Kara 已提交
782 783 784 785
	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
		ret = -EIO;
		goto out;
	}
786 787

	if (unlikely(file->f_flags & O_DIRECT))
788
		ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
789 790
	else
		ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
791
						  ocount);
792

793 794
	if (ret > 0) {
		ssize_t err;
795

796
		XFS_STATS_ADD(xs_write_bytes, ret);
797

798 799 800 801
		/* Handle various SYNC-type writes */
		err = generic_write_sync(file, pos, ret);
		if (err < 0)
			ret = err;
802 803
	}

J
Jan Kara 已提交
804
out:
805
	return ret;
806 807
}

808 809
STATIC long
xfs_file_fallocate(
810 811 812 813
	struct file		*file,
	int			mode,
	loff_t			offset,
	loff_t			len)
814
{
815 816 817 818 819
	struct inode		*inode = file_inode(file);
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_trans	*tp;
	long			error;
	loff_t			new_size = 0;
820

821 822
	if (!S_ISREG(inode->i_mode))
		return -EINVAL;
823 824 825 826
	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
		return -EOPNOTSUPP;

	xfs_ilock(ip, XFS_IOLOCK_EXCL);
827 828 829 830 831 832 833 834 835 836 837 838
	if (mode & FALLOC_FL_PUNCH_HOLE) {
		error = xfs_free_file_space(ip, offset, len);
		if (error)
			goto out_unlock;
	} else {
		if (!(mode & FALLOC_FL_KEEP_SIZE) &&
		    offset + len > i_size_read(inode)) {
			new_size = offset + len;
			error = -inode_newsize_ok(inode, new_size);
			if (error)
				goto out_unlock;
		}
839

840 841
		error = xfs_alloc_file_space(ip, offset, len,
					     XFS_BMAPI_PREALLOC);
842 843 844 845
		if (error)
			goto out_unlock;
	}

846 847 848 849 850 851 852 853 854 855 856 857
	tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
	error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
	if (error) {
		xfs_trans_cancel(tp, 0);
		goto out_unlock;
	}

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
	ip->i_d.di_mode &= ~S_ISUID;
	if (ip->i_d.di_mode & S_IXGRP)
		ip->i_d.di_mode &= ~S_ISGID;
858

859 860 861 862 863 864 865 866 867
	if (!(mode & FALLOC_FL_PUNCH_HOLE))
		ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;

	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

	if (file->f_flags & O_DSYNC)
		xfs_trans_set_sync(tp);
	error = xfs_trans_commit(tp, 0);
868 869 870 871 872 873 874 875 876
	if (error)
		goto out_unlock;

	/* Change file size if needed */
	if (new_size) {
		struct iattr iattr;

		iattr.ia_valid = ATTR_SIZE;
		iattr.ia_size = new_size;
877
		error = xfs_setattr_size(ip, &iattr);
878 879 880 881
	}

out_unlock:
	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
882
	return -error;
883 884 885
}


L
Linus Torvalds 已提交
886
STATIC int
887
xfs_file_open(
L
Linus Torvalds 已提交
888
	struct inode	*inode,
889
	struct file	*file)
L
Linus Torvalds 已提交
890
{
891
	if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
L
Linus Torvalds 已提交
892
		return -EFBIG;
893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914
	if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
		return -EIO;
	return 0;
}

STATIC int
xfs_dir_open(
	struct inode	*inode,
	struct file	*file)
{
	struct xfs_inode *ip = XFS_I(inode);
	int		mode;
	int		error;

	error = xfs_file_open(inode, file);
	if (error)
		return error;

	/*
	 * If there are any blocks, read-ahead block 0 as we're almost
	 * certain to have the next operation be a read there.
	 */
915
	mode = xfs_ilock_data_map_shared(ip);
916
	if (ip->i_d.di_nextents > 0)
917
		xfs_dir3_data_readahead(NULL, ip, 0, -1);
918 919
	xfs_iunlock(ip, mode);
	return 0;
L
Linus Torvalds 已提交
920 921 922
}

STATIC int
923
xfs_file_release(
L
Linus Torvalds 已提交
924 925 926
	struct inode	*inode,
	struct file	*filp)
{
927
	return -xfs_release(XFS_I(inode));
L
Linus Torvalds 已提交
928 929 930
}

STATIC int
931
xfs_file_readdir(
A
Al Viro 已提交
932 933
	struct file	*file,
	struct dir_context *ctx)
L
Linus Torvalds 已提交
934
{
A
Al Viro 已提交
935
	struct inode	*inode = file_inode(file);
936
	xfs_inode_t	*ip = XFS_I(inode);
C
Christoph Hellwig 已提交
937 938 939 940 941 942 943 944 945 946 947 948 949
	int		error;
	size_t		bufsize;

	/*
	 * The Linux API doesn't pass down the total size of the buffer
	 * we read into down to the filesystem.  With the filldir concept
	 * it's not needed for correct information, but the XFS dir2 leaf
	 * code wants an estimate of the buffer size to calculate it's
	 * readahead window and size the buffers used for mapping to
	 * physical blocks.
	 *
	 * Try to give it an estimate that's good enough, maybe at some
	 * point we can change the ->readdir prototype to include the
E
Eric Sandeen 已提交
950
	 * buffer size.  For now we use the current glibc buffer size.
C
Christoph Hellwig 已提交
951
	 */
E
Eric Sandeen 已提交
952
	bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
C
Christoph Hellwig 已提交
953

A
Al Viro 已提交
954
	error = xfs_readdir(ip, ctx, bufsize);
C
Christoph Hellwig 已提交
955 956 957
	if (error)
		return -error;
	return 0;
L
Linus Torvalds 已提交
958 959 960
}

STATIC int
961
xfs_file_mmap(
L
Linus Torvalds 已提交
962 963 964
	struct file	*filp,
	struct vm_area_struct *vma)
{
965
	vma->vm_ops = &xfs_file_vm_ops;
966

967
	file_accessed(filp);
L
Linus Torvalds 已提交
968 969 970
	return 0;
}

971 972 973 974 975 976 977 978 979
/*
 * mmap()d file has taken write protection fault and is being made
 * writable. We can set the page state up correctly for a writable
 * page, which means we can do correct delalloc accounting (ENOSPC
 * checking!) and unwritten extent mapping.
 */
STATIC int
xfs_vm_page_mkwrite(
	struct vm_area_struct	*vma,
980
	struct vm_fault		*vmf)
981
{
982
	return block_page_mkwrite(vma, vmf, xfs_get_blocks);
983 984
}

985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
/*
 * This type is designed to indicate the type of offset we would like
 * to search from page cache for either xfs_seek_data() or xfs_seek_hole().
 */
enum {
	HOLE_OFF = 0,
	DATA_OFF,
};

/*
 * Lookup the desired type of offset from the given page.
 *
 * On success, return true and the offset argument will point to the
 * start of the region that was found.  Otherwise this function will
 * return false and keep the offset argument unchanged.
 */
STATIC bool
xfs_lookup_buffer_offset(
	struct page		*page,
	loff_t			*offset,
	unsigned int		type)
{
	loff_t			lastoff = page_offset(page);
	bool			found = false;
	struct buffer_head	*bh, *head;

	bh = head = page_buffers(page);
	do {
		/*
		 * Unwritten extents that have data in the page
		 * cache covering them can be identified by the
		 * BH_Unwritten state flag.  Pages with multiple
		 * buffers might have a mix of holes, data and
		 * unwritten extents - any buffer with valid
		 * data in it should have BH_Uptodate flag set
		 * on it.
		 */
		if (buffer_unwritten(bh) ||
		    buffer_uptodate(bh)) {
			if (type == DATA_OFF)
				found = true;
		} else {
			if (type == HOLE_OFF)
				found = true;
		}

		if (found) {
			*offset = lastoff;
			break;
		}
		lastoff += bh->b_size;
	} while ((bh = bh->b_this_page) != head);

	return found;
}

/*
 * This routine is called to find out and return a data or hole offset
 * from the page cache for unwritten extents according to the desired
 * type for xfs_seek_data() or xfs_seek_hole().
 *
 * The argument offset is used to tell where we start to search from the
 * page cache.  Map is used to figure out the end points of the range to
 * lookup pages.
 *
 * Return true if the desired type of offset was found, and the argument
 * offset is filled with that address.  Otherwise, return false and keep
 * offset unchanged.
 */
STATIC bool
xfs_find_get_desired_pgoff(
	struct inode		*inode,
	struct xfs_bmbt_irec	*map,
	unsigned int		type,
	loff_t			*offset)
{
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	struct pagevec		pvec;
	pgoff_t			index;
	pgoff_t			end;
	loff_t			endoff;
	loff_t			startoff = *offset;
	loff_t			lastoff = startoff;
	bool			found = false;

	pagevec_init(&pvec, 0);

	index = startoff >> PAGE_CACHE_SHIFT;
	endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
	end = endoff >> PAGE_CACHE_SHIFT;
	do {
		int		want;
		unsigned	nr_pages;
		unsigned int	i;

		want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
		nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
					  want);
		/*
		 * No page mapped into given range.  If we are searching holes
		 * and if this is the first time we got into the loop, it means
		 * that the given offset is landed in a hole, return it.
		 *
		 * If we have already stepped through some block buffers to find
		 * holes but they all contains data.  In this case, the last
		 * offset is already updated and pointed to the end of the last
		 * mapped page, if it does not reach the endpoint to search,
		 * that means there should be a hole between them.
		 */
		if (nr_pages == 0) {
			/* Data search found nothing */
			if (type == DATA_OFF)
				break;

			ASSERT(type == HOLE_OFF);
			if (lastoff == startoff || lastoff < endoff) {
				found = true;
				*offset = lastoff;
			}
			break;
		}

		/*
		 * At lease we found one page.  If this is the first time we
		 * step into the loop, and if the first page index offset is
		 * greater than the given search offset, a hole was found.
		 */
		if (type == HOLE_OFF && lastoff == startoff &&
		    lastoff < page_offset(pvec.pages[0])) {
			found = true;
			break;
		}

		for (i = 0; i < nr_pages; i++) {
			struct page	*page = pvec.pages[i];
			loff_t		b_offset;

			/*
			 * At this point, the page may be truncated or
			 * invalidated (changing page->mapping to NULL),
			 * or even swizzled back from swapper_space to tmpfs
			 * file mapping. However, page->index will not change
			 * because we have a reference on the page.
			 *
			 * Searching done if the page index is out of range.
			 * If the current offset is not reaches the end of
			 * the specified search range, there should be a hole
			 * between them.
			 */
			if (page->index > end) {
				if (type == HOLE_OFF && lastoff < endoff) {
					*offset = lastoff;
					found = true;
				}
				goto out;
			}

			lock_page(page);
			/*
			 * Page truncated or invalidated(page->mapping == NULL).
			 * We can freely skip it and proceed to check the next
			 * page.
			 */
			if (unlikely(page->mapping != inode->i_mapping)) {
				unlock_page(page);
				continue;
			}

			if (!page_has_buffers(page)) {
				unlock_page(page);
				continue;
			}

			found = xfs_lookup_buffer_offset(page, &b_offset, type);
			if (found) {
				/*
				 * The found offset may be less than the start
				 * point to search if this is the first time to
				 * come here.
				 */
				*offset = max_t(loff_t, startoff, b_offset);
				unlock_page(page);
				goto out;
			}

			/*
			 * We either searching data but nothing was found, or
			 * searching hole but found a data buffer.  In either
			 * case, probably the next page contains the desired
			 * things, update the last offset to it so.
			 */
			lastoff = page_offset(page) + PAGE_SIZE;
			unlock_page(page);
		}

		/*
		 * The number of returned pages less than our desired, search
		 * done.  In this case, nothing was found for searching data,
		 * but we found a hole behind the last offset.
		 */
		if (nr_pages < want) {
			if (type == HOLE_OFF) {
				*offset = lastoff;
				found = true;
			}
			break;
		}

		index = pvec.pages[i - 1]->index + 1;
		pagevec_release(&pvec);
	} while (index <= end);

out:
	pagevec_release(&pvec);
	return found;
}

1203 1204 1205
STATIC loff_t
xfs_seek_data(
	struct file		*file,
1206
	loff_t			start)
1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
{
	struct inode		*inode = file->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	loff_t			uninitialized_var(offset);
	xfs_fsize_t		isize;
	xfs_fileoff_t		fsbno;
	xfs_filblks_t		end;
	uint			lock;
	int			error;

1218
	lock = xfs_ilock_data_map_shared(ip);
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229

	isize = i_size_read(inode);
	if (start >= isize) {
		error = ENXIO;
		goto out_unlock;
	}

	/*
	 * Try to read extents from the first block indicated
	 * by fsbno to the end block of the file.
	 */
1230
	fsbno = XFS_B_TO_FSBT(mp, start);
1231
	end = XFS_B_TO_FSB(mp, isize);
1232 1233 1234 1235
	for (;;) {
		struct xfs_bmbt_irec	map[2];
		int			nmap = 2;
		unsigned int		i;
1236

1237 1238 1239 1240
		error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
				       XFS_BMAPI_ENTIRE);
		if (error)
			goto out_unlock;
1241

1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
		/* No extents at given offset, must be beyond EOF */
		if (nmap == 0) {
			error = ENXIO;
			goto out_unlock;
		}

		for (i = 0; i < nmap; i++) {
			offset = max_t(loff_t, start,
				       XFS_FSB_TO_B(mp, map[i].br_startoff));

			/* Landed in a data extent */
			if (map[i].br_startblock == DELAYSTARTBLOCK ||
			    (map[i].br_state == XFS_EXT_NORM &&
			     !isnullstartblock(map[i].br_startblock)))
				goto out;

			/*
			 * Landed in an unwritten extent, try to search data
			 * from page cache.
			 */
			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
				if (xfs_find_get_desired_pgoff(inode, &map[i],
							DATA_OFF, &offset))
					goto out;
			}
		}

		/*
		 * map[0] is hole or its an unwritten extent but
		 * without data in page cache.  Probably means that
		 * we are reading after EOF if nothing in map[1].
		 */
1274 1275 1276 1277 1278
		if (nmap == 1) {
			error = ENXIO;
			goto out_unlock;
		}

1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
		ASSERT(i > 1);

		/*
		 * Nothing was found, proceed to the next round of search
		 * if reading offset not beyond or hit EOF.
		 */
		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
		start = XFS_FSB_TO_B(mp, fsbno);
		if (start >= isize) {
			error = ENXIO;
			goto out_unlock;
		}
1291 1292
	}

1293
out:
J
Jie Liu 已提交
1294
	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1295 1296

out_unlock:
1297
	xfs_iunlock(ip, lock);
1298 1299 1300 1301 1302 1303 1304 1305 1306

	if (error)
		return -error;
	return offset;
}

STATIC loff_t
xfs_seek_hole(
	struct file		*file,
1307
	loff_t			start)
1308 1309 1310 1311 1312 1313 1314
{
	struct inode		*inode = file->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	loff_t			uninitialized_var(offset);
	xfs_fsize_t		isize;
	xfs_fileoff_t		fsbno;
1315
	xfs_filblks_t		end;
1316 1317 1318 1319 1320 1321
	uint			lock;
	int			error;

	if (XFS_FORCED_SHUTDOWN(mp))
		return -XFS_ERROR(EIO);

1322
	lock = xfs_ilock_data_map_shared(ip);
1323 1324 1325 1326 1327 1328 1329 1330

	isize = i_size_read(inode);
	if (start >= isize) {
		error = ENXIO;
		goto out_unlock;
	}

	fsbno = XFS_B_TO_FSBT(mp, start);
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366
	end = XFS_B_TO_FSB(mp, isize);

	for (;;) {
		struct xfs_bmbt_irec	map[2];
		int			nmap = 2;
		unsigned int		i;

		error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
				       XFS_BMAPI_ENTIRE);
		if (error)
			goto out_unlock;

		/* No extents at given offset, must be beyond EOF */
		if (nmap == 0) {
			error = ENXIO;
			goto out_unlock;
		}

		for (i = 0; i < nmap; i++) {
			offset = max_t(loff_t, start,
				       XFS_FSB_TO_B(mp, map[i].br_startoff));

			/* Landed in a hole */
			if (map[i].br_startblock == HOLESTARTBLOCK)
				goto out;

			/*
			 * Landed in an unwritten extent, try to search hole
			 * from page cache.
			 */
			if (map[i].br_state == XFS_EXT_UNWRITTEN) {
				if (xfs_find_get_desired_pgoff(inode, &map[i],
							HOLE_OFF, &offset))
					goto out;
			}
		}
1367 1368

		/*
1369 1370 1371 1372 1373
		 * map[0] contains data or its unwritten but contains
		 * data in page cache, probably means that we are
		 * reading after EOF.  We should fix offset to point
		 * to the end of the file(i.e., there is an implicit
		 * hole at the end of any file).
1374
		 */
1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
		if (nmap == 1) {
			offset = isize;
			break;
		}

		ASSERT(i > 1);

		/*
		 * Both mappings contains data, proceed to the next round of
		 * search if the current reading offset not beyond or hit EOF.
		 */
		fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
		start = XFS_FSB_TO_B(mp, fsbno);
		if (start >= isize) {
			offset = isize;
			break;
		}
1392 1393
	}

1394 1395 1396 1397 1398 1399 1400 1401
out:
	/*
	 * At this point, we must have found a hole.  However, the returned
	 * offset may be bigger than the file size as it may be aligned to
	 * page boundary for unwritten extents, we need to deal with this
	 * situation in particular.
	 */
	offset = min_t(loff_t, offset, isize);
J
Jie Liu 已提交
1402
	offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1403 1404

out_unlock:
1405
	xfs_iunlock(ip, lock);
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423

	if (error)
		return -error;
	return offset;
}

STATIC loff_t
xfs_file_llseek(
	struct file	*file,
	loff_t		offset,
	int		origin)
{
	switch (origin) {
	case SEEK_END:
	case SEEK_CUR:
	case SEEK_SET:
		return generic_file_llseek(file, offset, origin);
	case SEEK_DATA:
1424
		return xfs_seek_data(file, offset);
1425
	case SEEK_HOLE:
1426
		return xfs_seek_hole(file, offset);
1427 1428 1429 1430 1431
	default:
		return -EINVAL;
	}
}

1432
const struct file_operations xfs_file_operations = {
1433
	.llseek		= xfs_file_llseek,
L
Linus Torvalds 已提交
1434
	.read		= do_sync_read,
1435
	.write		= do_sync_write,
1436 1437
	.aio_read	= xfs_file_aio_read,
	.aio_write	= xfs_file_aio_write,
1438 1439
	.splice_read	= xfs_file_splice_read,
	.splice_write	= xfs_file_splice_write,
1440
	.unlocked_ioctl	= xfs_file_ioctl,
L
Linus Torvalds 已提交
1441
#ifdef CONFIG_COMPAT
1442
	.compat_ioctl	= xfs_file_compat_ioctl,
L
Linus Torvalds 已提交
1443
#endif
1444 1445 1446 1447
	.mmap		= xfs_file_mmap,
	.open		= xfs_file_open,
	.release	= xfs_file_release,
	.fsync		= xfs_file_fsync,
1448
	.fallocate	= xfs_file_fallocate,
L
Linus Torvalds 已提交
1449 1450
};

1451
const struct file_operations xfs_dir_file_operations = {
1452
	.open		= xfs_dir_open,
L
Linus Torvalds 已提交
1453
	.read		= generic_read_dir,
A
Al Viro 已提交
1454
	.iterate	= xfs_file_readdir,
1455
	.llseek		= generic_file_llseek,
1456
	.unlocked_ioctl	= xfs_file_ioctl,
1457
#ifdef CONFIG_COMPAT
1458
	.compat_ioctl	= xfs_file_compat_ioctl,
1459
#endif
1460
	.fsync		= xfs_dir_fsync,
L
Linus Torvalds 已提交
1461 1462
};

1463
static const struct vm_operations_struct xfs_file_vm_ops = {
1464
	.fault		= filemap_fault,
1465
	.page_mkwrite	= xfs_vm_page_mkwrite,
1466
	.remap_pages	= generic_file_remap_pages,
1467
};