cregit-Linux how code gets into the kernel

Release 4.15 fs/xfs/xfs_file.c

Directory: fs/xfs
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * 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.
 *
 * 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
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_error.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_ioctl.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_icache.h"
#include "xfs_pnfs.h"
#include "xfs_iomap.h"
#include "xfs_reflink.h"

#include <linux/dcache.h>
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
#include <linux/mman.h>


static const struct vm_operations_struct xfs_file_vm_ops;

/*
 * Clear the specified ranges to zero through either the pagecache or DAX.
 * Holes and unwritten extents will be left as-is as they already are zeroed.
 */


int

xfs_zero_range(
	struct xfs_inode	*ip,
	xfs_off_t		pos,
	xfs_off_t		count,
	bool			*did_zero)
{
	return iomap_zero_range(VFS_I(ip), pos, count, did_zero, &xfs_iomap_ops);
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig2771.05%466.67%


Dave Chinner1026.32%116.67%


Eryu Guan12.63%116.67%


Total38100.00%6100.00%





int

xfs_update_prealloc_flags(
	struct xfs_inode	*ip,
	enum xfs_prealloc_flags	flags)
{
	struct xfs_trans	*tp;
	int			error;

	error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
			0, 0, 0, &tp);
	if (error)
		return error;

	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);

	if (!(flags & XFS_PREALLOC_INVISIBLE)) {
		VFS_I(ip)->i_mode &= ~S_ISUID;
		if (VFS_I(ip)->i_mode & S_IXGRP)
			VFS_I(ip)->i_mode &= ~S_ISGID;
		xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
	}

	if (flags & XFS_PREALLOC_SET)
		ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
	if (flags & XFS_PREALLOC_CLEAR)
		ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;

	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
	if (flags & XFS_PREALLOC_SYNC)
		xfs_trans_set_sync(tp);
	return xfs_trans_commit(tp);
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig16993.37%266.67%


Dave Chinner126.63%133.33%


Total181100.00%3100.00%



/*
 * 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);
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig102100.00%1100.00%


Total102100.00%1100.00%





STATIC int

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

	trace_xfs_file_fsync(ip);

	error = file_write_and_wait_range(file, start, end);
	if (error)
		return error;

	if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;

	xfs_iflags_clear(ip, XFS_ITRUNCATED);

	/*
         * 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);

	/*
         * All metadata updates are logged, which means that we just have to
         * flush the log up to the latest LSN that touched the inode. If we have
         * concurrent fsync/fdatasync() calls, we need them to all block on the
         * log force before we clear the ili_fsync_fields field. This ensures
         * that we don't get a racing sync operation that does not wait for the
         * metadata to hit the journal before returning. If we race with
         * clearing the ili_fsync_fields, then all that will happen is the log
         * force will do nothing as the lsn will already be on disk. We can't
         * race with setting ili_fsync_fields because that is done under
         * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared
         * until after the ili_fsync_fields is cleared.
         */
	xfs_ilock(ip, XFS_ILOCK_SHARED);
	if (xfs_ipincount(ip)) {
		if (!datasync ||
		    (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
			lsn = ip->i_itemp->ili_last_lsn;
	}

	if (lsn) {
		error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
		ip->i_itemp->ili_fsync_fields = 0;
	}
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	/*
         * 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 (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
	    mp->m_logdev_targp == mp->m_ddev_targp)
		xfs_blkdev_issue_flush(mp->m_ddev_targp);

	return error;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig19378.78%660.00%


Dave Chinner2811.43%220.00%


Josef Bacik228.98%110.00%


Jeff Layton20.82%110.00%


Total245100.00%10100.00%





STATIC ssize_t

xfs_file_dio_aio_read(
	struct kiocb		*iocb,
	struct iov_iter		*to)
{
	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
	size_t			count = iov_iter_count(to);
	ssize_t			ret;

	trace_xfs_file_direct_read(ip, count, iocb->ki_pos);

	if (!count)
		return 0; /* skip atime */

	file_accessed(iocb->ki_filp);

	xfs_ilock(ip, XFS_IOLOCK_SHARED);
	ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
	xfs_iunlock(ip, XFS_IOLOCK_SHARED);

	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig8282.00%1062.50%


Al Viro88.00%212.50%


Dave Chinner77.00%212.50%


Chris Mason22.00%16.25%


Bill O'Donnell11.00%16.25%


Total100100.00%16100.00%





static noinline ssize_t

xfs_file_dax_read(
	struct kiocb		*iocb,
	struct iov_iter		*to)
{
	struct xfs_inode	*ip = XFS_I(iocb->ki_filp->f_mapping->host);
	size_t			count = iov_iter_count(to);
	ssize_t			ret = 0;

	trace_xfs_file_dax_read(ip, count, iocb->ki_pos);

	if (!count)
		return 0; /* skip atime */

	if (iocb->ki_flags & IOCB_NOWAIT) {
		if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
			return -EAGAIN;
	} else {
		xfs_ilock(ip, XFS_IOLOCK_SHARED);
	}

	ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
	xfs_iunlock(ip, XFS_IOLOCK_SHARED);

	file_accessed(iocb->ki_filp);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig9875.97%960.00%


Goldwyn Rodrigues1511.63%16.67%


Dave Chinner107.75%213.33%


Bill O'Donnell32.33%16.67%


Arnd Bergmann21.55%16.67%


Ross Zwisler10.78%16.67%


Total129100.00%15100.00%





STATIC ssize_t

xfs_file_buffered_aio_read(
	struct kiocb		*iocb,
	struct iov_iter		*to)
{
	struct xfs_inode	*ip = XFS_I(file_inode(iocb->ki_filp));
	ssize_t			ret;

	trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);

	if (iocb->ki_flags & IOCB_NOWAIT) {
		if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
			return -EAGAIN;
	} else {
		xfs_ilock(ip, XFS_IOLOCK_SHARED);
	}
	ret = generic_file_read_iter(iocb, to);
	xfs_iunlock(ip, XFS_IOLOCK_SHARED);

	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig9695.05%770.00%


Dave Chinner21.98%110.00%


Al Viro21.98%110.00%


Brian Foster10.99%110.00%


Total101100.00%10100.00%





STATIC ssize_t

xfs_file_read_iter(
	struct kiocb		*iocb,
	struct iov_iter		*to)
{
	struct inode		*inode = file_inode(iocb->ki_filp);
	struct xfs_mount	*mp = XFS_I(inode)->i_mount;
	ssize_t			ret = 0;

	XFS_STATS_INC(mp, xs_read_calls);

	if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;

	if (IS_DAX(inode))
		ret = xfs_file_dax_read(iocb, to);
	else if (iocb->ki_flags & IOCB_DIRECT)
		ret = xfs_file_dio_aio_read(iocb, to);
	else
		ret = xfs_file_buffered_aio_read(iocb, to);

	if (ret > 0)
		XFS_STATS_ADD(mp, xs_read_bytes, ret);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig11491.20%450.00%


Dave Chinner54.00%225.00%


Al Viro43.20%112.50%


Bill O'Donnell21.60%112.50%


Total125100.00%8100.00%



/*
 * 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.
 */


int					/* error (positive) */

xfs_zero_eof(
	struct xfs_inode	*ip,
	xfs_off_t		offset,		/* starting I/O offset */
	xfs_fsize_t		isize,		/* current inode size */
	bool			*did_zeroing)
{
	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
	ASSERT(offset > isize);

	trace_xfs_zero_eof(ip, isize, offset - isize);
	return xfs_zero_range(ip, isize, offset - isize, did_zeroing);
}


Contributors
PersonTokensPropCommitsCommitProp
David Chinner3046.15%125.00%


Christoph Hellwig2436.92%250.00%


Brian Foster1116.92%125.00%


Total65100.00%4100.00%



/*
 * Common pre-write limit and setup checks.
 *
 * 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.
 */


STATIC ssize_t

xfs_file_aio_write_checks(
	struct kiocb		*iocb,
	struct iov_iter		*from,
	int			*iolock)
{
	struct file		*file = iocb->ki_filp;
	struct inode		*inode = file->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	ssize_t			error = 0;
	size_t			count = iov_iter_count(from);
	bool			drained_dio = false;

restart:
	error = generic_write_checks(iocb, from);
	if (error <= 0)
		return error;

	error = xfs_break_layouts(inode, iolock);
	if (error)
		return error;

	/*
         * For changing security info in file_remove_privs() we need i_rwsem
         * exclusively.
         */
	if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
		xfs_iunlock(ip, *iolock);
		*iolock = XFS_IOLOCK_EXCL;
		xfs_ilock(ip, *iolock);
		goto restart;
	}
	/*
         * 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
         * write.  If zeroing is needed and we are currently holding the
         * iolock shared, we need to update it to exclusive which implies
         * having to redo all checks before.
         *
         * We need to serialise against EOF updates that occur in IO
         * completions here. We want to make sure that nobody is changing the
         * size while we do this check until we have placed an IO barrier (i.e.
         * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
         * The spinlock effectively forms a memory barrier once we have the
         * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
         * and hence be able to correctly determine if we need to run zeroing.
         */
	spin_lock(&ip->i_flags_lock);
	if (iocb->ki_pos > i_size_read(inode)) {
		spin_unlock(&ip->i_flags_lock);
		if (!drained_dio) {
			if (*iolock == XFS_IOLOCK_SHARED) {
				xfs_iunlock(ip, *iolock);
				*iolock = XFS_IOLOCK_EXCL;
				xfs_ilock(ip, *iolock);
				iov_iter_reexpand(from, count);
			}
			/*
                         * We now have an IO submission barrier in place, but
                         * AIO can do EOF updates during IO completion and hence
                         * we now need to wait for all of them to drain. Non-AIO
                         * DIO will have drained before we are given the
                         * XFS_IOLOCK_EXCL, and so for most cases this wait is a
                         * no-op.
                         */
			inode_dio_wait(inode);
			drained_dio = true;
			goto restart;
		}
		error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), NULL);
		if (error)
			return error;
	} else
		spin_unlock(&ip->i_flags_lock);

	/*
         * 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.
         */
	if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
		error = file_update_time(file);
		if (error)
			return error;
	}

	/*
         * 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.
         */
	if (!IS_NOSEC(inode))
		return file_remove_privs(file);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig12238.85%738.89%


Dave Chinner8928.34%316.67%


Al Viro3511.15%211.11%


Jan Kara3310.51%211.11%


David Chinner206.37%15.56%


Brian Foster123.82%15.56%


Josef Bacik20.64%15.56%


Eryu Guan10.32%15.56%


Total314100.00%18100.00%





static int

xfs_dio_write_end_io(
	struct kiocb		*iocb,
	ssize_t			size,
	unsigned		flags)
{
	struct inode		*inode = file_inode(iocb->ki_filp);
	struct xfs_inode	*ip = XFS_I(inode);
	loff_t			offset = iocb->ki_pos;
	int			error = 0;

	trace_xfs_end_io_direct_write(ip, offset, size);

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

	if (size <= 0)
		return size;

	if (flags & IOMAP_DIO_COW) {
		error = xfs_reflink_end_cow(ip, offset, size);
		if (error)
			return error;
	}

	/*
         * Unwritten conversion updates the in-core isize after extent
         * conversion but before updating the on-disk size. Updating isize any
         * earlier allows a racing dio read to find unwritten extents before
         * they are converted.
         */
	if (flags & IOMAP_DIO_UNWRITTEN)
		return xfs_iomap_write_unwritten(ip, offset, size, true);

	/*
         * We need to update the in-core inode size here so that we don't end up
         * with the on-disk inode size being outside the in-core inode size. We
         * have no other method of updating EOF for AIO, so always do it here
         * if necessary.
         *
         * We need to lock the test/set EOF update as we can be racing with
         * other IO completions here to update the EOF. Failing to serialise
         * here can result in EOF moving backwards and Bad Things Happen when
         * that occurs.
         */
	spin_lock(&ip->i_flags_lock);
	if (offset + size > i_size_read(inode)) {
		i_size_write(inode, offset + size);
		spin_unlock(&ip->i_flags_lock);
		error = xfs_setfilesize(ip, offset, size);
	} else {
		spin_unlock(&ip->i_flags_lock);
	}

	return error;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig14073.30%150.00%


Eryu Guan5126.70%150.00%


Total191100.00%2100.00%



/*
 * xfs_file_dio_aio_write - handle direct IO writes
 *
 * Lock the inode appropriately to prepare for and issue a direct IO write.
 * By separating it from the buffered write path we remove all the tricky to
 * follow locking changes and looping.
 *
 * 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
 * hitting it with a big hammer (i.e. inode_dio_wait()).
 *
 * 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,
	struct iov_iter		*from)
{
	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;
	int			unaligned_io = 0;
	int			iolock;
	size_t			count = iov_iter_count(from);
	struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
					mp->m_rtdev_targp : mp->m_ddev_targp;

	/* DIO must be aligned to device logical sector size */
	if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
		return -EINVAL;

	/*
         * Don't take the exclusive iolock here unless the I/O is unaligned to
         * the file system block size.  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 ((iocb->ki_pos & mp->m_blockmask) ||
	    ((iocb->ki_pos + count) & mp->m_blockmask)) {
		unaligned_io = 1;

		/*
                 * We can't properly handle unaligned direct I/O to reflink
                 * files yet, as we can't unshare a partial block.
                 */
		if (xfs_is_reflink_inode(ip)) {
			trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count);
			return -EREMCHG;
		}
		iolock = XFS_IOLOCK_EXCL;
	} else {
		iolock = XFS_IOLOCK_SHARED;
	}

	if (iocb->ki_flags & IOCB_NOWAIT) {
		if (!xfs_ilock_nowait(ip, iolock))
			return -EAGAIN;
	} else {
		xfs_ilock(ip, iolock);
	}

	ret = xfs_file_aio_write_checks(iocb, from, &iolock);
	if (ret)
		goto out;
	count = iov_iter_count(from);

	/*
         * If we are doing unaligned IO, wait for all other IO to drain,
         * otherwise demote the lock if we had to take the exclusive lock
         * for other reasons in xfs_file_aio_write_checks.
         */
	if (unaligned_io) {
		/* If we are going to wait for other DIO to finish, bail */
		if (iocb->ki_flags & IOCB_NOWAIT) {
			if (atomic_read(&inode->i_dio_count))
				return -EAGAIN;
		} else {
			inode_dio_wait(inode);
		}
	} else if (iolock == XFS_IOLOCK_EXCL) {
		xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
		iolock = XFS_IOLOCK_SHARED;
	}

	trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
	ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
out:
	xfs_iunlock(ip, iolock);

	/*
         * No fallback to buffered IO on errors for XFS, direct IO will either
         * complete fully or fail.
         */
	ASSERT(ret < 0 || ret == count);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner15342.74%723.33%


Christoph Hellwig8824.58%1446.67%


Goldwyn Rodrigues4512.57%13.33%


Al Viro359.78%310.00%


David Chinner246.70%13.33%


Jan Kara61.68%13.33%


Eric Sandeen41.12%26.67%


Brian Foster30.84%13.33%


Total358100.00%30100.00%





static noinline ssize_t

xfs_file_dax_write(
	struct kiocb		*iocb,
	struct iov_iter		*from)
{
	struct inode		*inode = iocb->ki_filp->f_mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	int			iolock = XFS_IOLOCK_EXCL;
	ssize_t			ret, error = 0;
	size_t			count;
	loff_t			pos;

	if (iocb->ki_flags & IOCB_NOWAIT) {
		if (!xfs_ilock_nowait(ip, iolock))
			return -EAGAIN;
	} else {
		xfs_ilock(ip, iolock);
	}

	ret = xfs_file_aio_write_checks(iocb, from, &iolock);
	if (ret)
		goto out;

	pos = iocb->ki_pos;
	count = iov_iter_count(from);

	trace_xfs_file_dax_write(ip, count, pos);
	ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
	if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
		i_size_write(inode, iocb->ki_pos);
		error = xfs_setfilesize(ip, pos, ret);
	}
out:
	xfs_iunlock(ip, iolock);
	return error ? error : ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner9045.45%527.78%


Christoph Hellwig8643.43%844.44%


Goldwyn Rodrigues157.58%15.56%


Al Viro42.02%211.11%


Arnd Bergmann21.01%15.56%


Ross Zwisler10.51%15.56%


Total198100.00%18100.00%





STATIC ssize_t

xfs_file_buffered_aio_write(
	struct kiocb		*iocb,
	struct iov_iter		*from)
{
	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;
	int			enospc = 0;
	int			iolock;

	if (iocb->ki_flags & IOCB_NOWAIT)
		return -EOPNOTSUPP;

write_retry:
	iolock = XFS_IOLOCK_EXCL;
	xfs_ilock(ip, iolock);

	ret = xfs_file_aio_write_checks(iocb, from, &iolock);
	if (ret)
		goto out;

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = inode_to_bdi(inode);

	trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos);
	ret = iomap_file_buffered_write(iocb, from, &xfs_iomap_ops);
	if (likely(ret >= 0))
		iocb->ki_pos += ret;

	/*
         * If we hit a space limit, try to free up some lingering preallocated
         * space before returning an error. In the case of ENOSPC, first try to
         * write back all dirty inodes to free up some of the excess reserved
         * metadata space. This reduces the chances that the eofblocks scan
         * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
         * also behaves as a filter to prevent too many eofblocks scans from
         * running at the same time.
         */
	if (ret == -EDQUOT && !enospc) {
		xfs_iunlock(ip, iolock);
		enospc = xfs_inode_free_quota_eofblocks(ip);
		if (enospc)
			goto write_retry;
		enospc = xfs_inode_free_quota_cowblocks(ip);
		if (enospc)
			goto write_retry;
		iolock = 0;
	} else if (ret == -ENOSPC && !enospc) {
		struct xfs_eofblocks eofb = {0};

		enospc = 1;
		xfs_flush_inodes(ip->i_mount);

		xfs_iunlock(ip, iolock);
		eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
		xfs_icache_free_eofblocks(ip->i_mount, &eofb);
		xfs_icache_free_cowblocks(ip->i_mount, &eofb);
		goto write_retry;
	}

	current->backing_dev_info = NULL;
out:
	if (iolock)
		xfs_iunlock(ip, iolock);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig16153.49%738.89%


Brian Foster9029.90%316.67%


Al Viro206.64%316.67%


Dave Chinner165.32%422.22%


Darrick J. Wong144.65%15.56%


Total301100.00%18100.00%





STATIC ssize_t

xfs_file_write_iter(
	struct kiocb		*iocb,
	struct iov_iter		*from)
{
	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 = iov_iter_count(from);

	XFS_STATS_INC(ip->i_mount, xs_write_calls);

	if (ocount == 0)
		return 0;

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

	if (IS_DAX(inode))
		ret = xfs_file_dax_write(iocb, from);
	else if (iocb->ki_flags & IOCB_DIRECT) {
		/*
                 * Allow a directio write to fall back to a buffered
                 * write *only* in the case that we're doing a reflink
                 * CoW.  In all other directio scenarios we do not
                 * allow an operation to fall back to buffered mode.
                 */
		ret = xfs_file_dio_aio_write(iocb, from);
		if (ret == -EREMCHG)
			goto buffered;
	} else {
buffered:
		ret = xfs_file_buffered_aio_write(iocb, from);
	}

	if (ret > 0) {
		XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);

		/* Handle various SYNC-type writes */
		ret = generic_write_sync(iocb, ret);
	}
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner10455.32%214.29%


Christoph Hellwig4322.87%535.71%


Darrick J. Wong179.04%17.14%


Al Viro157.98%428.57%


Bill O'Donnell84.26%17.14%


Josef Bacik10.53%17.14%


Total188100.00%14100.00%




#define	XFS_FALLOC_FL_SUPPORTED						\
		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |           \
                 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |      \
                 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)



STATIC long

xfs_file_fallocate(
	struct file		*file,
	int			mode,
	loff_t			offset,
	loff_t			len)
{
	struct inode		*inode = file_inode(file);
	struct xfs_inode	*ip = XFS_I(inode);
	long			error;
	enum xfs_prealloc_flags	flags = 0;
	uint			iolock = XFS_IOLOCK_EXCL;
	loff_t			new_size = 0;
	bool			do_file_insert = false;

	if (!S_ISREG(inode->i_mode))
		return -EINVAL;
	if (mode & ~XFS_FALLOC_FL_SUPPORTED)
		return -EOPNOTSUPP;

	xfs_ilock(ip, iolock);
	error = xfs_break_layouts(inode, &iolock);
	if (error)
		goto out_unlock;

	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
	iolock |= XFS_MMAPLOCK_EXCL;

	if (mode & FALLOC_FL_PUNCH_HOLE) {
		error = xfs_free_file_space(ip, offset, len);
		if (error)
			goto out_unlock;
	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
		unsigned int blksize_mask = i_blocksize(inode) - 1;

		if (offset & blksize_mask || len & blksize_mask) {
			error = -EINVAL;
			goto out_unlock;
		}

		/*
                 * There is no need to overlap collapse range with EOF,
                 * in which case it is effectively a truncate operation
                 */
		if (offset + len >= i_size_read(inode)) {
			error = -EINVAL;
			goto out_unlock;
		}

		new_size = i_size_read(inode) - len;

		error = xfs_collapse_file_space(ip, offset, len);
		if (error)
			goto out_unlock;
	} else if (mode & FALLOC_FL_INSERT_RANGE) {
		unsigned int blksize_mask = i_blocksize(inode) - 1;

		new_size = i_size_read(inode) + len;
		if (offset & blksize_mask || len & blksize_mask) {
			error = -EINVAL;
			goto out_unlock;
		}

		/* check the new inode size does not wrap through zero */
		if (new_size > inode->i_sb->s_maxbytes) {
			error = -EFBIG;
			goto out_unlock;
		}

		/* Offset should be less than i_size */
		if (offset >= i_size_read(inode)) {
			error = -EINVAL;
			goto out_unlock;
		}
		do_file_insert = true;
	} else {
		flags |= XFS_PREALLOC_SET;

		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;
		}

		if (mode & FALLOC_FL_ZERO_RANGE)
			error = xfs_zero_file_space(ip, offset, len);
		else {
			if (mode & FALLOC_FL_UNSHARE_RANGE) {
				error = xfs_reflink_unshare(ip, offset, len);
				if (error)
					goto out_unlock;
			}
			error = xfs_alloc_file_space(ip, offset, len,
						     XFS_BMAPI_PREALLOC);
		}
		if (error)
			goto out_unlock;
	}

	if (file->f_flags & O_DSYNC)
		flags |= XFS_PREALLOC_SYNC;

	error = xfs_update_prealloc_flags(ip, flags);
	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;
		error = xfs_vn_setattr_size(file_dentry(file), &iattr);
		if (error)
			goto out_unlock;
	}

	/*
         * Perform hole insertion now that the file size has been
         * updated so that if we crash during the operation we don't
         * leave shifted extents past EOF and hence losing access to
         * the data that is contained within them.
         */
	if (do_file_insert)
		error = xfs_insert_file_space(ip, offset, len);

out_unlock:
	xfs_iunlock(ip, iolock);
	return error;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig26648.63%633.33%


Namjae Jeon18734.19%211.11%


Lukas Czerner315.67%211.11%


Darrick J. Wong285.12%15.56%


Dave Chinner173.11%316.67%


Fabian Frederick81.46%15.56%


Jan Kara50.91%15.56%


Al Viro30.55%15.56%


Thomas Meyer20.37%15.56%


Total547100.00%18100.00%





STATIC int

xfs_file_clone_range(
	struct file	*file_in,
	loff_t		pos_in,
	struct file	*file_out,
	loff_t		pos_out,
	u64		len)
{
	return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
				     len, false);
}


Contributors
PersonTokensPropCommitsCommitProp
Darrick J. Wong3175.61%266.67%


Christoph Hellwig1024.39%133.33%


Total41100.00%3100.00%





STATIC ssize_t

xfs_file_dedupe_range(
	struct file	*src_file,
	u64		loff,
	u64		len,
	struct file	*dst_file,
	u64		dst_loff)
{
	int		error;

	error = xfs_reflink_remap_range(src_file, loff, dst_file, dst_loff,
				     len, true);
	if (error)
		return error;
	return len;
}


Contributors
PersonTokensPropCommitsCommitProp
Darrick J. Wong5498.18%266.67%


Christoph Hellwig11.82%133.33%


Total55100.00%3100.00%





STATIC int

xfs_file_open(
	struct inode	*inode,
	struct file	*file)
{
	if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
		return -EFBIG;
	if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
		return -EIO;
	file->f_mode |= FMODE_NOWAIT;
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig5282.54%450.00%


Goldwyn Rodrigues57.94%112.50%


Nathan Scott34.76%225.00%


Stephen Lord34.76%112.50%


Total63100.00%8100.00%





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.
         */
	mode = xfs_ilock_data_map_shared(ip);
	if (ip->i_d.di_nextents > 0)
		error = xfs_dir3_data_readahead(ip, 0, -1);
	xfs_iunlock(ip, mode);
	return error;
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig7989.77%450.00%


Darrick J. Wong33.41%112.50%


Nathan Scott33.41%112.50%


Dave Chinner33.41%225.00%


Total88100.00%8100.00%





STATIC int

xfs_file_release(
	struct inode	*inode,
	struct file	*filp)
{
	return xfs_release(XFS_I(inode));
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig2392.00%250.00%


Nathan Scott28.00%250.00%


Total25100.00%4100.00%





STATIC int

xfs_file_readdir(
	struct file	*file,
	struct dir_context *ctx)
{
	struct inode	*inode = file_inode(file);
	xfs_inode_t	*ip = XFS_I(inode);
	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
         * buffer size.  For now we use the current glibc buffer size.
         */
	bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_d.di_size);

	return xfs_readdir(NULL, ip, ctx, bufsize);
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig3753.62%533.33%


David Woodhouse1217.39%16.67%


Al Viro913.04%213.33%


Lachlan McIlroy45.80%16.67%


Darrick J. Wong34.35%213.33%


Nathan Scott22.90%213.33%


Fengguang Wu11.45%16.67%


Eric Sandeen11.45%16.67%


Total69100.00%15100.00%





STATIC loff_t

xfs_file_llseek(
	struct file	*file,
	loff_t		offset,
	int		whence)
{
	struct inode		*inode = file->f_mapping->host;

	if (XFS_FORCED_SHUTDOWN(XFS_I(inode)->i_mount))
		return -EIO;

	switch (whence) {
	default:
		return generic_file_llseek(file, offset, whence);
	case SEEK_HOLE:
		offset = iomap_seek_hole(inode, offset, &xfs_iomap_ops);
		break;
	case SEEK_DATA:
		offset = iomap_seek_data(inode, offset, &xfs_iomap_ops);
		break;
	}

	if (offset < 0)
		return offset;
	return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
}


Contributors
PersonTokensPropCommitsCommitProp
Jie Liu6051.72%457.14%


Christoph Hellwig3025.86%114.29%


Eric Sandeen2521.55%114.29%


Jan Kara10.86%114.29%


Total116100.00%7100.00%



/*
 * Locking for serialisation of IO during page faults. This results in a lock
 * ordering of:
 *
 * mmap_sem (MM)
 *   sb_start_pagefault(vfs, freeze)
 *     i_mmaplock (XFS - truncate serialisation)
 *       page_lock (MM)
 *         i_lock (XFS - extent map serialisation)
 */


static int

__xfs_filemap_fault(
	struct vm_fault		*vmf,
	enum page_entry_size	pe_size,
	bool			write_fault)
{
	struct inode		*inode = file_inode(vmf->vma->vm_file);
	struct xfs_inode	*ip = XFS_I(inode);
	int			ret;

	trace_xfs_filemap_fault(ip, pe_size, write_fault);

	if (write_fault) {
		sb_start_pagefault(inode->i_sb);
		file_update_time(vmf->vma->vm_file);
	}

	xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
	if (IS_DAX(inode)) {
		pfn_t pfn;

		ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
		if (ret & VM_FAULT_NEEDDSYNC)
			ret = dax_finish_sync_fault(vmf, pe_size, pfn);
	} else {
		if (write_fault)
			ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
		else
			ret = filemap_fault(vmf);
	}
	xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);

	if (write_fault)
		sb_end_pagefault(inode->i_sb);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner9754.19%220.00%


Christoph Hellwig7541.90%440.00%


Dave Jiang52.79%220.00%


Ross Zwisler10.56%110.00%


Jan Kara10.56%110.00%


Total179100.00%10100.00%





static int

xfs_filemap_fault(
	struct vm_fault		*vmf)
{
	/* DAX can shortcut the normal fault path on write faults! */
	return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
			IS_DAX(file_inode(vmf->vma->vm_file)) &&
			(vmf->flags & FAULT_FLAG_WRITE));
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner2665.00%360.00%


Christoph Hellwig1230.00%120.00%


Dave Jiang25.00%120.00%


Total40100.00%5100.00%





static int

xfs_filemap_huge_fault(
	struct vm_fault		*vmf,
	enum page_entry_size	pe_size)
{
	if (!IS_DAX(file_inode(vmf->vma->vm_file)))
		return VM_FAULT_FALLBACK;

	/* DAX can shortcut the normal fault path on write faults! */
	return __xfs_filemap_fault(vmf, pe_size,
			(vmf->flags & FAULT_FLAG_WRITE));
}


Contributors
PersonTokensPropCommitsCommitProp
Matthew Wilcox1938.00%114.29%


Christoph Hellwig1632.00%114.29%


Dave Jiang1122.00%457.14%


Dave Chinner48.00%114.29%


Total50100.00%7100.00%





static int

xfs_filemap_page_mkwrite(
	struct vm_fault		*vmf)
{
	return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}


Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig1466.67%133.33%


Matthew Wilcox628.57%133.33%


Dave Jiang14.76%133.33%


Total21100.00%3100.00%



/*
 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
 * on write faults. In reality, it needs to serialise against truncate and
 * prepare memory for writing so handle is as standard write fault.
 */


static int

xfs_filemap_pfn_mkwrite(
	struct vm_fault		*vmf)
{

	return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner1047.62%120.00%


Ross Zwisler523.81%240.00%


Matthew Wilcox314.29%120.00%


Jan Kara314.29%120.00%


Total21100.00%5100.00%




static const struct vm_operations_struct xfs_file_vm_ops = {
	.fault		= xfs_filemap_fault,
	.huge_fault	= xfs_filemap_huge_fault,
	.map_pages	= filemap_map_pages,
	.page_mkwrite	= xfs_filemap_page_mkwrite,
	.pfn_mkwrite	= xfs_filemap_pfn_mkwrite,
};



STATIC int

xfs_file_mmap(
	struct file	*filp,
	struct vm_area_struct *vma)
{
	/*
         * We don't support synchronous mappings for non-DAX files. At least
         * until someone comes with a sensible use case.
         */
	if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
		return -EOPNOTSUPP;

	file_accessed(filp);
	vma->vm_ops = &xfs_file_vm_ops;
	if (IS_DAX(file_inode(filp)))
		vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Dave Chinner4764.38%360.00%


Christoph Hellwig2432.88%120.00%


Matthew Wilcox22.74%120.00%


Total73100.00%5100.00%




const struct file_operations xfs_file_operations = {
	.llseek		= xfs_file_llseek,
	.read_iter	= xfs_file_read_iter,
	.write_iter	= xfs_file_write_iter,
	.splice_read	= generic_file_splice_read,
	.splice_write	= iter_file_splice_write,
	.unlocked_ioctl	= xfs_file_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= xfs_file_compat_ioctl,
#endif
	.mmap		= xfs_file_mmap,
	.mmap_supported_flags = MAP_SYNC,
	.open		= xfs_file_open,
	.release	= xfs_file_release,
	.fsync		= xfs_file_fsync,
	.get_unmapped_area = thp_get_unmapped_area,
	.fallocate	= xfs_file_fallocate,
	.clone_file_range = xfs_file_clone_range,
	.dedupe_file_range = xfs_file_dedupe_range,
};


const struct file_operations xfs_dir_file_operations = {
	.open		= xfs_dir_open,
	.read		= generic_read_dir,
	.iterate_shared	= xfs_file_readdir,
	.llseek		= generic_file_llseek,
	.unlocked_ioctl	= xfs_file_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= xfs_file_compat_ioctl,
#endif
	.fsync		= xfs_dir_fsync,
};

Overall Contributors
PersonTokensPropCommitsCommitProp
Christoph Hellwig227752.93%5832.58%


Dave Chinner78818.32%3519.66%


Namjae Jeon1914.44%21.12%


Darrick J. Wong1643.81%84.49%


Al Viro1473.42%158.43%


Brian Foster1202.79%52.81%


Goldwyn Rodrigues801.86%10.56%


David Chinner751.74%21.12%


Jie Liu641.49%42.25%


Eryu Guan531.23%31.69%


Jan Kara501.16%63.37%


Nathan Scott400.93%52.81%


Matthew Wilcox330.77%10.56%


Lukas Czerner310.72%21.12%


Eric Sandeen300.70%42.25%


Josef Bacik250.58%21.12%


Dave Jiang210.49%52.81%


Stephen Lord160.37%21.12%


Russell Cattelan160.37%10.56%


Bill O'Donnell140.33%10.56%


Andi Kleen130.30%10.56%


David Woodhouse120.28%10.56%


Ross Zwisler80.19%31.69%


Fabian Frederick80.19%10.56%


Toshi Kani50.12%10.56%


Arnd Bergmann40.09%10.56%


Lachlan McIlroy40.09%10.56%


Tejun Heo30.07%10.56%


Thomas Meyer20.05%10.56%


Jeff Layton20.05%10.56%


Chris Mason20.05%10.56%


Arjan van de Ven20.05%10.56%


Fengguang Wu10.02%10.56%


Alexey Dobriyan10.02%10.56%


Total4302100.00%178100.00%


Directory: fs/xfs



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