acfbac7764
xfs_file_write_zero_eof is the only caller of xfs_zero_range that does not take XFS_MMAPLOCK_EXCL (aka the invalidate lock). Currently that is actually the right thing, as an error in the iomap zeroing code will also take the invalidate_lock to clean up, but to fix that deadlock we need a consistent locking pattern first. The only extra thing that XFS_MMAPLOCK_EXCL will lock out are read pagefaults, which isn't really needed here, but also not actively harmful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
1612 lines
41 KiB
C
1612 lines
41 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*/
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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"
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#include "xfs_trans_resv.h"
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#include "xfs_mount.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_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_icache.h"
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#include "xfs_pnfs.h"
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#include "xfs_iomap.h"
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#include "xfs_reflink.h"
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#include "xfs_file.h"
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#include <linux/dax.h>
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#include <linux/falloc.h>
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#include <linux/backing-dev.h>
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#include <linux/mman.h>
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#include <linux/fadvise.h>
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#include <linux/mount.h>
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static const struct vm_operations_struct xfs_file_vm_ops;
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/*
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* Decide if the given file range is aligned to the size of the fundamental
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* allocation unit for the file.
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*/
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bool
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xfs_is_falloc_aligned(
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struct xfs_inode *ip,
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loff_t pos,
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long long int len)
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{
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unsigned int alloc_unit = xfs_inode_alloc_unitsize(ip);
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if (!is_power_of_2(alloc_unit))
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return isaligned_64(pos, alloc_unit) &&
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isaligned_64(len, alloc_unit);
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return !((pos | len) & (alloc_unit - 1));
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}
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/*
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* Fsync operations on directories are much simpler than on regular files,
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* as there is no file data to flush, and thus also no need for explicit
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* cache flush operations, and there are no non-transaction metadata updates
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* on directories either.
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*/
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STATIC int
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xfs_dir_fsync(
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struct file *file,
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loff_t start,
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loff_t end,
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int datasync)
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{
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struct xfs_inode *ip = XFS_I(file->f_mapping->host);
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trace_xfs_dir_fsync(ip);
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return xfs_log_force_inode(ip);
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}
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static xfs_csn_t
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xfs_fsync_seq(
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struct xfs_inode *ip,
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bool datasync)
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{
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if (!xfs_ipincount(ip))
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return 0;
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if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
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return 0;
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return ip->i_itemp->ili_commit_seq;
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}
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/*
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* All metadata updates are logged, which means that we just have to flush the
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* log up to the latest LSN that touched the inode.
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*
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* If we have concurrent fsync/fdatasync() calls, we need them to all block on
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* the log force before we clear the ili_fsync_fields field. This ensures that
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* we don't get a racing sync operation that does not wait for the metadata to
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* hit the journal before returning. If we race with clearing ili_fsync_fields,
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* then all that will happen is the log force will do nothing as the lsn will
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* already be on disk. We can't race with setting ili_fsync_fields because that
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* is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock
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* shared until after the ili_fsync_fields is cleared.
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*/
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static int
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xfs_fsync_flush_log(
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struct xfs_inode *ip,
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bool datasync,
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int *log_flushed)
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{
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int error = 0;
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xfs_csn_t seq;
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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seq = xfs_fsync_seq(ip, datasync);
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if (seq) {
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error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC,
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log_flushed);
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spin_lock(&ip->i_itemp->ili_lock);
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ip->i_itemp->ili_fsync_fields = 0;
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spin_unlock(&ip->i_itemp->ili_lock);
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}
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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return error;
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}
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STATIC int
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xfs_file_fsync(
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struct file *file,
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loff_t start,
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loff_t end,
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int datasync)
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{
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struct xfs_inode *ip = XFS_I(file->f_mapping->host);
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struct xfs_mount *mp = ip->i_mount;
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int error, err2;
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int log_flushed = 0;
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trace_xfs_file_fsync(ip);
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error = file_write_and_wait_range(file, start, end);
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if (error)
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return error;
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if (xfs_is_shutdown(mp))
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return -EIO;
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xfs_iflags_clear(ip, XFS_ITRUNCATED);
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/*
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* If we have an RT and/or log subvolume we need to make sure to flush
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* the write cache the device used for file data first. This is to
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* ensure newly written file data make it to disk before logging the new
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* inode size in case of an extending write.
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*/
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if (XFS_IS_REALTIME_INODE(ip))
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error = blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
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else if (mp->m_logdev_targp != mp->m_ddev_targp)
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error = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
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/*
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* Any inode that has dirty modifications in the log is pinned. The
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* racy check here for a pinned inode will not catch modifications
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* that happen concurrently to the fsync call, but fsync semantics
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* only require to sync previously completed I/O.
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*/
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if (xfs_ipincount(ip)) {
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err2 = xfs_fsync_flush_log(ip, datasync, &log_flushed);
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if (err2 && !error)
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error = err2;
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}
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/*
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* If we only have a single device, and the log force about was
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* a no-op we might have to flush the data device cache here.
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* This can only happen for fdatasync/O_DSYNC if we were overwriting
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* an already allocated file and thus do not have any metadata to
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* commit.
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*/
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if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
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mp->m_logdev_targp == mp->m_ddev_targp) {
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err2 = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
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if (err2 && !error)
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error = err2;
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}
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return error;
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}
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static int
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xfs_ilock_iocb(
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struct kiocb *iocb,
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unsigned int lock_mode)
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{
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struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
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if (iocb->ki_flags & IOCB_NOWAIT) {
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if (!xfs_ilock_nowait(ip, lock_mode))
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return -EAGAIN;
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} else {
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xfs_ilock(ip, lock_mode);
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}
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return 0;
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}
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static int
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xfs_ilock_iocb_for_write(
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struct kiocb *iocb,
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unsigned int *lock_mode)
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{
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ssize_t ret;
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struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
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ret = xfs_ilock_iocb(iocb, *lock_mode);
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if (ret)
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return ret;
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/*
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* If a reflink remap is in progress we always need to take the iolock
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* exclusively to wait for it to finish.
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*/
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if (*lock_mode == XFS_IOLOCK_SHARED &&
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xfs_iflags_test(ip, XFS_IREMAPPING)) {
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xfs_iunlock(ip, *lock_mode);
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*lock_mode = XFS_IOLOCK_EXCL;
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return xfs_ilock_iocb(iocb, *lock_mode);
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}
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return 0;
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}
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STATIC ssize_t
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xfs_file_dio_read(
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struct kiocb *iocb,
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struct iov_iter *to)
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{
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struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
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ssize_t ret;
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trace_xfs_file_direct_read(iocb, to);
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if (!iov_iter_count(to))
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return 0; /* skip atime */
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file_accessed(iocb->ki_filp);
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ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
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if (ret)
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return ret;
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ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0, NULL, 0);
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
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}
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static noinline ssize_t
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xfs_file_dax_read(
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struct kiocb *iocb,
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struct iov_iter *to)
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{
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struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
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ssize_t ret = 0;
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trace_xfs_file_dax_read(iocb, to);
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if (!iov_iter_count(to))
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return 0; /* skip atime */
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ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
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if (ret)
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return ret;
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ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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file_accessed(iocb->ki_filp);
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return ret;
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}
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STATIC ssize_t
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xfs_file_buffered_read(
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struct kiocb *iocb,
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struct iov_iter *to)
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{
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struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
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ssize_t ret;
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trace_xfs_file_buffered_read(iocb, to);
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ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
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if (ret)
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return ret;
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ret = generic_file_read_iter(iocb, to);
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
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}
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STATIC ssize_t
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xfs_file_read_iter(
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struct kiocb *iocb,
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struct iov_iter *to)
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{
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struct inode *inode = file_inode(iocb->ki_filp);
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struct xfs_mount *mp = XFS_I(inode)->i_mount;
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ssize_t ret = 0;
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XFS_STATS_INC(mp, xs_read_calls);
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if (xfs_is_shutdown(mp))
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return -EIO;
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if (IS_DAX(inode))
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ret = xfs_file_dax_read(iocb, to);
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else if (iocb->ki_flags & IOCB_DIRECT)
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ret = xfs_file_dio_read(iocb, to);
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else
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ret = xfs_file_buffered_read(iocb, to);
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if (ret > 0)
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XFS_STATS_ADD(mp, xs_read_bytes, ret);
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return ret;
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}
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STATIC ssize_t
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xfs_file_splice_read(
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struct file *in,
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loff_t *ppos,
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struct pipe_inode_info *pipe,
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size_t len,
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unsigned int flags)
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{
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struct inode *inode = file_inode(in);
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struct xfs_inode *ip = XFS_I(inode);
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struct xfs_mount *mp = ip->i_mount;
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ssize_t ret = 0;
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XFS_STATS_INC(mp, xs_read_calls);
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if (xfs_is_shutdown(mp))
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return -EIO;
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trace_xfs_file_splice_read(ip, *ppos, len);
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xfs_ilock(ip, XFS_IOLOCK_SHARED);
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ret = filemap_splice_read(in, ppos, pipe, len, flags);
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xfs_iunlock(ip, XFS_IOLOCK_SHARED);
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if (ret > 0)
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XFS_STATS_ADD(mp, xs_read_bytes, ret);
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return ret;
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}
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/*
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* Take care of zeroing post-EOF blocks when they might exist.
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*
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* Returns 0 if successfully, a negative error for a failure, or 1 if this
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* function dropped the iolock and reacquired it exclusively and the caller
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* needs to restart the write sanity checks.
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*/
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static ssize_t
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xfs_file_write_zero_eof(
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struct kiocb *iocb,
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struct iov_iter *from,
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unsigned int *iolock,
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size_t count,
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bool *drained_dio)
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{
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struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
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loff_t isize;
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int error;
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/*
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* We need to serialise against EOF updates that occur in IO completions
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* here. We want to make sure that nobody is changing the size while
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* we do this check until we have placed an IO barrier (i.e. hold
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* XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The
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* spinlock effectively forms a memory barrier once we have
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* XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and
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* hence be able to correctly determine if we need to run zeroing.
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*/
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spin_lock(&ip->i_flags_lock);
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isize = i_size_read(VFS_I(ip));
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if (iocb->ki_pos <= isize) {
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spin_unlock(&ip->i_flags_lock);
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return 0;
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}
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spin_unlock(&ip->i_flags_lock);
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|
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if (iocb->ki_flags & IOCB_NOWAIT)
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return -EAGAIN;
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|
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if (!*drained_dio) {
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/*
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* If zeroing is needed and we are currently holding the iolock
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* shared, we need to update it to exclusive which implies
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* having to redo all checks before.
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*/
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if (*iolock == XFS_IOLOCK_SHARED) {
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xfs_iunlock(ip, *iolock);
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*iolock = XFS_IOLOCK_EXCL;
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xfs_ilock(ip, *iolock);
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iov_iter_reexpand(from, count);
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}
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|
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/*
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* We now have an IO submission barrier in place, but AIO can do
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* EOF updates during IO completion and hence we now need to
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* wait for all of them to drain. Non-AIO DIO will have drained
|
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* before we are given the XFS_IOLOCK_EXCL, and so for most
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* cases this wait is a no-op.
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*/
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inode_dio_wait(VFS_I(ip));
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*drained_dio = true;
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return 1;
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}
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|
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trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
|
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|
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xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
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error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL);
|
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xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
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|
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return error;
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}
|
|
|
|
/*
|
|
* Common pre-write limit and setup checks.
|
|
*
|
|
* Called with the iolock held either shared and exclusive according to
|
|
* @iolock, and returns with it held. Might upgrade the iolock to exclusive
|
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* if called for a direct write beyond i_size.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_write_checks(
|
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struct kiocb *iocb,
|
|
struct iov_iter *from,
|
|
unsigned int *iolock)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
size_t count = iov_iter_count(from);
|
|
bool drained_dio = false;
|
|
ssize_t error;
|
|
|
|
restart:
|
|
error = generic_write_checks(iocb, from);
|
|
if (error <= 0)
|
|
return error;
|
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) {
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|
error = break_layout(inode, false);
|
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if (error == -EWOULDBLOCK)
|
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error = -EAGAIN;
|
|
} else {
|
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error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
|
|
}
|
|
|
|
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(XFS_I(inode), *iolock);
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*iolock = XFS_IOLOCK_EXCL;
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error = xfs_ilock_iocb(iocb, *iolock);
|
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if (error) {
|
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*iolock = 0;
|
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return error;
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}
|
|
goto restart;
|
|
}
|
|
|
|
/*
|
|
* If the offset is beyond the size of the file, we need to zero all
|
|
* blocks that fall between the existing EOF and the start of this
|
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* write.
|
|
*
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|
* We can do an unlocked check for i_size here safely as I/O completion
|
|
* can only extend EOF. Truncate is locked out at this point, so the
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* EOF can not move backwards, only forwards. Hence we only need to take
|
|
* the slow path when we are at or beyond the current EOF.
|
|
*/
|
|
if (iocb->ki_pos > i_size_read(inode)) {
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|
error = xfs_file_write_zero_eof(iocb, from, iolock, count,
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&drained_dio);
|
|
if (error == 1)
|
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goto restart;
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
return kiocb_modified(iocb);
|
|
}
|
|
|
|
static int
|
|
xfs_dio_write_end_io(
|
|
struct kiocb *iocb,
|
|
ssize_t size,
|
|
int error,
|
|
unsigned flags)
|
|
{
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
loff_t offset = iocb->ki_pos;
|
|
unsigned int nofs_flag;
|
|
|
|
trace_xfs_end_io_direct_write(ip, offset, size);
|
|
|
|
if (xfs_is_shutdown(ip->i_mount))
|
|
return -EIO;
|
|
|
|
if (error)
|
|
return error;
|
|
if (!size)
|
|
return 0;
|
|
|
|
/*
|
|
* Capture amount written on completion as we can't reliably account
|
|
* for it on submission.
|
|
*/
|
|
XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
|
|
|
|
/*
|
|
* We can allocate memory here while doing writeback on behalf of
|
|
* memory reclaim. To avoid memory allocation deadlocks set the
|
|
* task-wide nofs context for the following operations.
|
|
*/
|
|
nofs_flag = memalloc_nofs_save();
|
|
|
|
if (flags & IOMAP_DIO_COW) {
|
|
error = xfs_reflink_end_cow(ip, offset, size);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
error = xfs_iomap_write_unwritten(ip, offset, size, true);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* As IO completion only ever extends EOF, we can do an unlocked check
|
|
* here to avoid taking the spinlock. If we land within the current EOF,
|
|
* then we do not need to do an extending update at all, and we don't
|
|
* need to take the lock to check this. If we race with an update moving
|
|
* EOF, then we'll either still be beyond EOF and need to take the lock,
|
|
* or we'll be within EOF and we don't need to take it at all.
|
|
*/
|
|
if (offset + size <= i_size_read(inode))
|
|
goto out;
|
|
|
|
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);
|
|
}
|
|
|
|
out:
|
|
memalloc_nofs_restore(nofs_flag);
|
|
return error;
|
|
}
|
|
|
|
static const struct iomap_dio_ops xfs_dio_write_ops = {
|
|
.end_io = xfs_dio_write_end_io,
|
|
};
|
|
|
|
/*
|
|
* Handle block aligned direct I/O writes
|
|
*/
|
|
static noinline ssize_t
|
|
xfs_file_dio_write_aligned(
|
|
struct xfs_inode *ip,
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
unsigned int iolock = XFS_IOLOCK_SHARED;
|
|
ssize_t ret;
|
|
|
|
ret = xfs_ilock_iocb_for_write(iocb, &iolock);
|
|
if (ret)
|
|
return ret;
|
|
ret = xfs_file_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* We don't need to hold the IOLOCK exclusively across the IO, so demote
|
|
* the iolock back to shared if we had to take the exclusive lock in
|
|
* xfs_file_write_checks() for other reasons.
|
|
*/
|
|
if (iolock == XFS_IOLOCK_EXCL) {
|
|
xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
}
|
|
trace_xfs_file_direct_write(iocb, from);
|
|
ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
|
|
&xfs_dio_write_ops, 0, NULL, 0);
|
|
out_unlock:
|
|
if (iolock)
|
|
xfs_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Handle block unaligned direct I/O writes
|
|
*
|
|
* In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing
|
|
* them to be done in parallel with reads and other direct I/O writes. However,
|
|
* if the I/O is not aligned to filesystem blocks, the direct I/O layer may need
|
|
* to do sub-block zeroing and that requires serialisation against other direct
|
|
* I/O to the same block. In this case we need to serialise the submission of
|
|
* the unaligned I/O so that we don't get racing block zeroing in the dio layer.
|
|
* In the case where sub-block zeroing is not required, we can do concurrent
|
|
* sub-block dios to the same block successfully.
|
|
*
|
|
* Optimistically submit the I/O using the shared lock first, but use the
|
|
* IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN
|
|
* if block allocation or partial block zeroing would be required. In that case
|
|
* we try again with the exclusive lock.
|
|
*/
|
|
static noinline ssize_t
|
|
xfs_file_dio_write_unaligned(
|
|
struct xfs_inode *ip,
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
size_t isize = i_size_read(VFS_I(ip));
|
|
size_t count = iov_iter_count(from);
|
|
unsigned int iolock = XFS_IOLOCK_SHARED;
|
|
unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY;
|
|
ssize_t ret;
|
|
|
|
/*
|
|
* Extending writes need exclusivity because of the sub-block zeroing
|
|
* that the DIO code always does for partial tail blocks beyond EOF, so
|
|
* don't even bother trying the fast path in this case.
|
|
*/
|
|
if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) {
|
|
if (iocb->ki_flags & IOCB_NOWAIT)
|
|
return -EAGAIN;
|
|
retry_exclusive:
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
flags = IOMAP_DIO_FORCE_WAIT;
|
|
}
|
|
|
|
ret = xfs_ilock_iocb_for_write(iocb, &iolock);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* We can't properly handle unaligned direct I/O to reflink files yet,
|
|
* as we can't unshare a partial block.
|
|
*/
|
|
if (xfs_is_cow_inode(ip)) {
|
|
trace_xfs_reflink_bounce_dio_write(iocb, from);
|
|
ret = -ENOTBLK;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = xfs_file_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* If we are doing exclusive unaligned I/O, this must be the only I/O
|
|
* in-flight. Otherwise we risk data corruption due to unwritten extent
|
|
* conversions from the AIO end_io handler. Wait for all other I/O to
|
|
* drain first.
|
|
*/
|
|
if (flags & IOMAP_DIO_FORCE_WAIT)
|
|
inode_dio_wait(VFS_I(ip));
|
|
|
|
trace_xfs_file_direct_write(iocb, from);
|
|
ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
|
|
&xfs_dio_write_ops, flags, NULL, 0);
|
|
|
|
/*
|
|
* Retry unaligned I/O with exclusive blocking semantics if the DIO
|
|
* layer rejected it for mapping or locking reasons. If we are doing
|
|
* nonblocking user I/O, propagate the error.
|
|
*/
|
|
if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) {
|
|
ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY);
|
|
xfs_iunlock(ip, iolock);
|
|
goto retry_exclusive;
|
|
}
|
|
|
|
out_unlock:
|
|
if (iolock)
|
|
xfs_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
xfs_file_dio_write(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
|
|
struct xfs_buftarg *target = xfs_inode_buftarg(ip);
|
|
size_t count = iov_iter_count(from);
|
|
|
|
/* direct I/O must be aligned to device logical sector size */
|
|
if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
|
|
return -EINVAL;
|
|
if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask)
|
|
return xfs_file_dio_write_unaligned(ip, iocb, from);
|
|
return xfs_file_dio_write_aligned(ip, iocb, from);
|
|
}
|
|
|
|
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);
|
|
unsigned int iolock = XFS_IOLOCK_EXCL;
|
|
ssize_t ret, error = 0;
|
|
loff_t pos;
|
|
|
|
ret = xfs_ilock_iocb(iocb, iolock);
|
|
if (ret)
|
|
return ret;
|
|
ret = xfs_file_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
pos = iocb->ki_pos;
|
|
|
|
trace_xfs_file_dax_write(iocb, from);
|
|
ret = dax_iomap_rw(iocb, from, &xfs_dax_write_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:
|
|
if (iolock)
|
|
xfs_iunlock(ip, iolock);
|
|
if (error)
|
|
return error;
|
|
|
|
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;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_buffered_write(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
bool cleared_space = false;
|
|
unsigned int iolock;
|
|
|
|
write_retry:
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
ret = xfs_ilock_iocb(iocb, iolock);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = xfs_file_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
trace_xfs_file_buffered_write(iocb, from);
|
|
ret = iomap_file_buffered_write(iocb, from,
|
|
&xfs_buffered_write_iomap_ops, NULL);
|
|
|
|
/*
|
|
* 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. Use a synchronous scan to increase the
|
|
* effectiveness of the scan.
|
|
*/
|
|
if (ret == -EDQUOT && !cleared_space) {
|
|
xfs_iunlock(ip, iolock);
|
|
xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC);
|
|
cleared_space = true;
|
|
goto write_retry;
|
|
} else if (ret == -ENOSPC && !cleared_space) {
|
|
struct xfs_icwalk icw = {0};
|
|
|
|
cleared_space = true;
|
|
xfs_flush_inodes(ip->i_mount);
|
|
|
|
xfs_iunlock(ip, iolock);
|
|
icw.icw_flags = XFS_ICWALK_FLAG_SYNC;
|
|
xfs_blockgc_free_space(ip->i_mount, &icw);
|
|
goto write_retry;
|
|
}
|
|
|
|
out:
|
|
if (iolock)
|
|
xfs_iunlock(ip, iolock);
|
|
|
|
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;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_write_iter(
|
|
struct kiocb *iocb,
|
|
struct iov_iter *from)
|
|
{
|
|
struct inode *inode = iocb->ki_filp->f_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_is_shutdown(ip->i_mount))
|
|
return -EIO;
|
|
|
|
if (IS_DAX(inode))
|
|
return xfs_file_dax_write(iocb, from);
|
|
|
|
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_write(iocb, from);
|
|
if (ret != -ENOTBLK)
|
|
return ret;
|
|
}
|
|
|
|
return xfs_file_buffered_write(iocb, from);
|
|
}
|
|
|
|
/* Does this file, inode, or mount want synchronous writes? */
|
|
static inline bool xfs_file_sync_writes(struct file *filp)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file_inode(filp));
|
|
|
|
if (xfs_has_wsync(ip->i_mount))
|
|
return true;
|
|
if (filp->f_flags & (__O_SYNC | O_DSYNC))
|
|
return true;
|
|
if (IS_SYNC(file_inode(filp)))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_newsize(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len,
|
|
loff_t *new_size)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
|
|
if ((mode & FALLOC_FL_KEEP_SIZE) || offset + len <= i_size_read(inode))
|
|
return 0;
|
|
*new_size = offset + len;
|
|
return inode_newsize_ok(inode, *new_size);
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_setsize(
|
|
struct file *file,
|
|
loff_t new_size)
|
|
{
|
|
struct iattr iattr = {
|
|
.ia_valid = ATTR_SIZE,
|
|
.ia_size = new_size,
|
|
};
|
|
|
|
if (!new_size)
|
|
return 0;
|
|
return xfs_vn_setattr_size(file_mnt_idmap(file), file_dentry(file),
|
|
&iattr);
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_collapse_range(
|
|
struct file *file,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
loff_t new_size = i_size_read(inode) - len;
|
|
int error;
|
|
|
|
if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* 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))
|
|
return -EINVAL;
|
|
|
|
error = xfs_collapse_file_space(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
return xfs_falloc_setsize(file, new_size);
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_insert_range(
|
|
struct file *file,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
loff_t isize = i_size_read(inode);
|
|
int error;
|
|
|
|
if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* New inode size must not exceed ->s_maxbytes, accounting for
|
|
* possible signed overflow.
|
|
*/
|
|
if (inode->i_sb->s_maxbytes - isize < len)
|
|
return -EFBIG;
|
|
|
|
/* Offset should be less than i_size */
|
|
if (offset >= isize)
|
|
return -EINVAL;
|
|
|
|
error = xfs_falloc_setsize(file, isize + len);
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
return xfs_insert_file_space(XFS_I(inode), offset, len);
|
|
}
|
|
|
|
/*
|
|
* Punch a hole and prealloc the range. We use a hole punch rather than
|
|
* unwritten extent conversion for two reasons:
|
|
*
|
|
* 1.) Hole punch handles partial block zeroing for us.
|
|
* 2.) If prealloc returns ENOSPC, the file range is still zero-valued by
|
|
* virtue of the hole punch.
|
|
*/
|
|
static int
|
|
xfs_falloc_zero_range(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
unsigned int blksize = i_blocksize(inode);
|
|
loff_t new_size = 0;
|
|
int error;
|
|
|
|
trace_xfs_zero_file_space(XFS_I(inode));
|
|
|
|
error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
|
|
if (error)
|
|
return error;
|
|
|
|
error = xfs_free_file_space(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
|
|
len = round_up(offset + len, blksize) - round_down(offset, blksize);
|
|
offset = round_down(offset, blksize);
|
|
error = xfs_alloc_file_space(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
return xfs_falloc_setsize(file, new_size);
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_unshare_range(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
loff_t new_size = 0;
|
|
int error;
|
|
|
|
error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
|
|
if (error)
|
|
return error;
|
|
|
|
error = xfs_reflink_unshare(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
|
|
error = xfs_alloc_file_space(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
return xfs_falloc_setsize(file, new_size);
|
|
}
|
|
|
|
static int
|
|
xfs_falloc_allocate_range(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
loff_t new_size = 0;
|
|
int error;
|
|
|
|
/*
|
|
* If always_cow mode we can't use preallocations and thus should not
|
|
* create them.
|
|
*/
|
|
if (xfs_is_always_cow_inode(XFS_I(inode)))
|
|
return -EOPNOTSUPP;
|
|
|
|
error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
|
|
if (error)
|
|
return error;
|
|
|
|
error = xfs_alloc_file_space(XFS_I(inode), offset, len);
|
|
if (error)
|
|
return error;
|
|
return xfs_falloc_setsize(file, new_size);
|
|
}
|
|
|
|
#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;
|
|
uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
|
|
|
|
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, BREAK_UNMAP);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* Must wait for all AIO to complete before we continue as AIO can
|
|
* change the file size on completion without holding any locks we
|
|
* currently hold. We must do this first because AIO can update both
|
|
* the on disk and in memory inode sizes, and the operations that follow
|
|
* require the in-memory size to be fully up-to-date.
|
|
*/
|
|
inode_dio_wait(inode);
|
|
|
|
error = file_modified(file);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
switch (mode & FALLOC_FL_MODE_MASK) {
|
|
case FALLOC_FL_PUNCH_HOLE:
|
|
error = xfs_free_file_space(ip, offset, len);
|
|
break;
|
|
case FALLOC_FL_COLLAPSE_RANGE:
|
|
error = xfs_falloc_collapse_range(file, offset, len);
|
|
break;
|
|
case FALLOC_FL_INSERT_RANGE:
|
|
error = xfs_falloc_insert_range(file, offset, len);
|
|
break;
|
|
case FALLOC_FL_ZERO_RANGE:
|
|
error = xfs_falloc_zero_range(file, mode, offset, len);
|
|
break;
|
|
case FALLOC_FL_UNSHARE_RANGE:
|
|
error = xfs_falloc_unshare_range(file, mode, offset, len);
|
|
break;
|
|
case FALLOC_FL_ALLOCATE_RANGE:
|
|
error = xfs_falloc_allocate_range(file, mode, offset, len);
|
|
break;
|
|
default:
|
|
error = -EOPNOTSUPP;
|
|
break;
|
|
}
|
|
|
|
if (!error && xfs_file_sync_writes(file))
|
|
error = xfs_log_force_inode(ip);
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, iolock);
|
|
return error;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_fadvise(
|
|
struct file *file,
|
|
loff_t start,
|
|
loff_t end,
|
|
int advice)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file_inode(file));
|
|
int ret;
|
|
int lockflags = 0;
|
|
|
|
/*
|
|
* Operations creating pages in page cache need protection from hole
|
|
* punching and similar ops
|
|
*/
|
|
if (advice == POSIX_FADV_WILLNEED) {
|
|
lockflags = XFS_IOLOCK_SHARED;
|
|
xfs_ilock(ip, lockflags);
|
|
}
|
|
ret = generic_fadvise(file, start, end, advice);
|
|
if (lockflags)
|
|
xfs_iunlock(ip, lockflags);
|
|
return ret;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_file_remap_range(
|
|
struct file *file_in,
|
|
loff_t pos_in,
|
|
struct file *file_out,
|
|
loff_t pos_out,
|
|
loff_t len,
|
|
unsigned int remap_flags)
|
|
{
|
|
struct inode *inode_in = file_inode(file_in);
|
|
struct xfs_inode *src = XFS_I(inode_in);
|
|
struct inode *inode_out = file_inode(file_out);
|
|
struct xfs_inode *dest = XFS_I(inode_out);
|
|
struct xfs_mount *mp = src->i_mount;
|
|
loff_t remapped = 0;
|
|
xfs_extlen_t cowextsize;
|
|
int ret;
|
|
|
|
if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
|
|
return -EINVAL;
|
|
|
|
if (!xfs_has_reflink(mp))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (xfs_is_shutdown(mp))
|
|
return -EIO;
|
|
|
|
/* Prepare and then clone file data. */
|
|
ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
|
|
&len, remap_flags);
|
|
if (ret || len == 0)
|
|
return ret;
|
|
|
|
trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
|
|
|
|
ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
|
|
&remapped);
|
|
if (ret)
|
|
goto out_unlock;
|
|
|
|
/*
|
|
* Carry the cowextsize hint from src to dest if we're sharing the
|
|
* entire source file to the entire destination file, the source file
|
|
* has a cowextsize hint, and the destination file does not.
|
|
*/
|
|
cowextsize = 0;
|
|
if (pos_in == 0 && len == i_size_read(inode_in) &&
|
|
(src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
|
|
pos_out == 0 && len >= i_size_read(inode_out) &&
|
|
!(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE))
|
|
cowextsize = src->i_cowextsize;
|
|
|
|
ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
|
|
remap_flags);
|
|
if (ret)
|
|
goto out_unlock;
|
|
|
|
if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
|
|
xfs_log_force_inode(dest);
|
|
out_unlock:
|
|
xfs_iunlock2_remapping(src, dest);
|
|
if (ret)
|
|
trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
|
|
return remapped > 0 ? remapped : ret;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
if (xfs_is_shutdown(XFS_M(inode->i_sb)))
|
|
return -EIO;
|
|
file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT;
|
|
return generic_file_open(inode, file);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_dir_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
unsigned int mode;
|
|
int error;
|
|
|
|
if (xfs_is_shutdown(ip->i_mount))
|
|
return -EIO;
|
|
error = generic_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_df.if_nextents > 0)
|
|
error = xfs_dir3_data_readahead(ip, 0, 0);
|
|
xfs_iunlock(ip, mode);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Don't bother propagating errors. We're just doing cleanup, and the caller
|
|
* ignores the return value anyway.
|
|
*/
|
|
STATIC int
|
|
xfs_file_release(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
|
|
/*
|
|
* If this is a read-only mount or the file system has been shut down,
|
|
* don't generate I/O.
|
|
*/
|
|
if (xfs_is_readonly(mp) || xfs_is_shutdown(mp))
|
|
return 0;
|
|
|
|
/*
|
|
* If we previously truncated this file and removed old data in the
|
|
* process, we want to initiate "early" writeout on the last close.
|
|
* This is an attempt to combat the notorious NULL files problem which
|
|
* is particularly noticeable from a truncate down, buffered (re-)write
|
|
* (delalloc), followed by a crash. What we are effectively doing here
|
|
* is significantly reducing the time window where we'd otherwise be
|
|
* exposed to that problem.
|
|
*/
|
|
if (xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED)) {
|
|
xfs_iflags_clear(ip, XFS_EOFBLOCKS_RELEASED);
|
|
if (ip->i_delayed_blks > 0)
|
|
filemap_flush(inode->i_mapping);
|
|
}
|
|
|
|
/*
|
|
* XFS aggressively preallocates post-EOF space to generate contiguous
|
|
* allocations for writers that append to the end of the file.
|
|
*
|
|
* To support workloads that close and reopen the file frequently, these
|
|
* preallocations usually persist after a close unless it is the first
|
|
* close for the inode. This is a tradeoff to generate tightly packed
|
|
* data layouts for unpacking tarballs or similar archives that write
|
|
* one file after another without going back to it while keeping the
|
|
* preallocation for files that have recurring open/write/close cycles.
|
|
*
|
|
* This heuristic is skipped for inodes with the append-only flag as
|
|
* that flag is rather pointless for inodes written only once.
|
|
*
|
|
* There is no point in freeing blocks here for open but unlinked files
|
|
* as they will be taken care of by the inactivation path soon.
|
|
*
|
|
* When releasing a read-only context, don't flush data or trim post-EOF
|
|
* blocks. This avoids open/read/close workloads from removing EOF
|
|
* blocks that other writers depend upon to reduce fragmentation.
|
|
*
|
|
* If we can't get the iolock just skip truncating the blocks past EOF
|
|
* because we could deadlock with the mmap_lock otherwise. We'll get
|
|
* another chance to drop them once the last reference to the inode is
|
|
* dropped, so we'll never leak blocks permanently.
|
|
*/
|
|
if (inode->i_nlink &&
|
|
(file->f_mode & FMODE_WRITE) &&
|
|
!(ip->i_diflags & XFS_DIFLAG_APPEND) &&
|
|
!xfs_iflags_test(ip, XFS_EOFBLOCKS_RELEASED) &&
|
|
xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
|
|
if (xfs_can_free_eofblocks(ip) &&
|
|
!xfs_iflags_test_and_set(ip, XFS_EOFBLOCKS_RELEASED))
|
|
xfs_free_eofblocks(ip);
|
|
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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_disk_size);
|
|
|
|
return xfs_readdir(NULL, ip, ctx, bufsize);
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_file_llseek(
|
|
struct file *file,
|
|
loff_t offset,
|
|
int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
|
|
if (xfs_is_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_seek_iomap_ops);
|
|
break;
|
|
case SEEK_DATA:
|
|
offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
|
|
break;
|
|
}
|
|
|
|
if (offset < 0)
|
|
return offset;
|
|
return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
|
|
}
|
|
|
|
static inline vm_fault_t
|
|
xfs_dax_fault_locked(
|
|
struct vm_fault *vmf,
|
|
unsigned int order,
|
|
bool write_fault)
|
|
{
|
|
vm_fault_t ret;
|
|
pfn_t pfn;
|
|
|
|
if (!IS_ENABLED(CONFIG_FS_DAX)) {
|
|
ASSERT(0);
|
|
return VM_FAULT_SIGBUS;
|
|
}
|
|
ret = dax_iomap_fault(vmf, order, &pfn, NULL,
|
|
(write_fault && !vmf->cow_page) ?
|
|
&xfs_dax_write_iomap_ops :
|
|
&xfs_read_iomap_ops);
|
|
if (ret & VM_FAULT_NEEDDSYNC)
|
|
ret = dax_finish_sync_fault(vmf, order, pfn);
|
|
return ret;
|
|
}
|
|
|
|
static vm_fault_t
|
|
xfs_dax_read_fault(
|
|
struct vm_fault *vmf,
|
|
unsigned int order)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file_inode(vmf->vma->vm_file));
|
|
vm_fault_t ret;
|
|
|
|
xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
|
|
ret = xfs_dax_fault_locked(vmf, order, false);
|
|
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static vm_fault_t
|
|
xfs_write_fault(
|
|
struct vm_fault *vmf,
|
|
unsigned int order)
|
|
{
|
|
struct inode *inode = file_inode(vmf->vma->vm_file);
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
unsigned int lock_mode = XFS_MMAPLOCK_SHARED;
|
|
vm_fault_t ret;
|
|
|
|
sb_start_pagefault(inode->i_sb);
|
|
file_update_time(vmf->vma->vm_file);
|
|
|
|
/*
|
|
* Normally we only need the shared mmaplock, but if a reflink remap is
|
|
* in progress we take the exclusive lock to wait for the remap to
|
|
* finish before taking a write fault.
|
|
*/
|
|
xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
|
|
if (xfs_iflags_test(ip, XFS_IREMAPPING)) {
|
|
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
|
|
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
|
|
lock_mode = XFS_MMAPLOCK_EXCL;
|
|
}
|
|
|
|
if (IS_DAX(inode))
|
|
ret = xfs_dax_fault_locked(vmf, order, true);
|
|
else
|
|
ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
|
|
xfs_iunlock(ip, lock_mode);
|
|
|
|
sb_end_pagefault(inode->i_sb);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Locking for serialisation of IO during page faults. This results in a lock
|
|
* ordering of:
|
|
*
|
|
* mmap_lock (MM)
|
|
* sb_start_pagefault(vfs, freeze)
|
|
* invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation)
|
|
* page_lock (MM)
|
|
* i_lock (XFS - extent map serialisation)
|
|
*/
|
|
static vm_fault_t
|
|
__xfs_filemap_fault(
|
|
struct vm_fault *vmf,
|
|
unsigned int order,
|
|
bool write_fault)
|
|
{
|
|
struct inode *inode = file_inode(vmf->vma->vm_file);
|
|
|
|
trace_xfs_filemap_fault(XFS_I(inode), order, write_fault);
|
|
|
|
if (write_fault)
|
|
return xfs_write_fault(vmf, order);
|
|
if (IS_DAX(inode))
|
|
return xfs_dax_read_fault(vmf, order);
|
|
return filemap_fault(vmf);
|
|
}
|
|
|
|
static inline bool
|
|
xfs_is_write_fault(
|
|
struct vm_fault *vmf)
|
|
{
|
|
return (vmf->flags & FAULT_FLAG_WRITE) &&
|
|
(vmf->vma->vm_flags & VM_SHARED);
|
|
}
|
|
|
|
static vm_fault_t
|
|
xfs_filemap_fault(
|
|
struct vm_fault *vmf)
|
|
{
|
|
/* DAX can shortcut the normal fault path on write faults! */
|
|
return __xfs_filemap_fault(vmf, 0,
|
|
IS_DAX(file_inode(vmf->vma->vm_file)) &&
|
|
xfs_is_write_fault(vmf));
|
|
}
|
|
|
|
static vm_fault_t
|
|
xfs_filemap_huge_fault(
|
|
struct vm_fault *vmf,
|
|
unsigned int order)
|
|
{
|
|
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, order,
|
|
xfs_is_write_fault(vmf));
|
|
}
|
|
|
|
static vm_fault_t
|
|
xfs_filemap_page_mkwrite(
|
|
struct vm_fault *vmf)
|
|
{
|
|
return __xfs_filemap_fault(vmf, 0, true);
|
|
}
|
|
|
|
/*
|
|
* 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 vm_fault_t
|
|
xfs_filemap_pfn_mkwrite(
|
|
struct vm_fault *vmf)
|
|
{
|
|
|
|
return __xfs_filemap_fault(vmf, 0, true);
|
|
}
|
|
|
|
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 *file,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode));
|
|
|
|
/*
|
|
* We don't support synchronous mappings for non-DAX files and
|
|
* for DAX files if underneath dax_device is not synchronous.
|
|
*/
|
|
if (!daxdev_mapping_supported(vma, target->bt_daxdev))
|
|
return -EOPNOTSUPP;
|
|
|
|
file_accessed(file);
|
|
vma->vm_ops = &xfs_file_vm_ops;
|
|
if (IS_DAX(inode))
|
|
vm_flags_set(vma, VM_HUGEPAGE);
|
|
return 0;
|
|
}
|
|
|
|
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 = xfs_file_splice_read,
|
|
.splice_write = iter_file_splice_write,
|
|
.iopoll = iocb_bio_iopoll,
|
|
.unlocked_ioctl = xfs_file_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = xfs_file_compat_ioctl,
|
|
#endif
|
|
.mmap = xfs_file_mmap,
|
|
.open = xfs_file_open,
|
|
.release = xfs_file_release,
|
|
.fsync = xfs_file_fsync,
|
|
.get_unmapped_area = thp_get_unmapped_area,
|
|
.fallocate = xfs_file_fallocate,
|
|
.fadvise = xfs_file_fadvise,
|
|
.remap_file_range = xfs_file_remap_range,
|
|
.fop_flags = FOP_MMAP_SYNC | FOP_BUFFER_RASYNC |
|
|
FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE,
|
|
};
|
|
|
|
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,
|
|
};
|