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https://github.com/edk2-porting/linux-next.git
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b2442c5a7f
When modifying the patch series to handle the XFS MMAP_LOCK nesting of page faults, I botched the conversion of the read page fault path, and so it is only every calling through the page cache. Re-add the necessary __dax_fault() call for such files. Because the get_blocks callback on read faults may not set up the mapping buffer correctly to allow unwritten extent completion to be run, we need to allow callers of __dax_fault() to pass a null complete_unwritten() callback. The DAX code always zeros the unwritten page when it is read faulted so there are no stale data exposure issues with not doing the conversion. The only downside will be the potential for increased CPU overhead on repeated read faults of the same page. If this proves to be a problem, then the filesystem needs to fix it's get_block callback and provide a convert_unwritten() callback to the read fault path. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
1588 lines
41 KiB
C
1588 lines
41 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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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_da_format.h"
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#include "xfs_da_btree.h"
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#include "xfs_inode.h"
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#include "xfs_trans.h"
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#include "xfs_inode_item.h"
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#include "xfs_bmap.h"
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#include "xfs_bmap_util.h"
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#include "xfs_error.h"
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#include "xfs_dir2.h"
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#include "xfs_dir2_priv.h"
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#include "xfs_ioctl.h"
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#include "xfs_trace.h"
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#include "xfs_log.h"
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#include "xfs_icache.h"
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#include "xfs_pnfs.h"
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#include <linux/dcache.h>
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#include <linux/falloc.h>
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#include <linux/pagevec.h>
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#include <linux/backing-dev.h>
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static const struct vm_operations_struct xfs_file_vm_ops;
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/*
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* Locking primitives for read and write IO paths to ensure we consistently use
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* and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
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*/
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static inline void
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xfs_rw_ilock(
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struct xfs_inode *ip,
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int type)
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{
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if (type & XFS_IOLOCK_EXCL)
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mutex_lock(&VFS_I(ip)->i_mutex);
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xfs_ilock(ip, type);
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}
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static inline void
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xfs_rw_iunlock(
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struct xfs_inode *ip,
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int type)
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{
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xfs_iunlock(ip, type);
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if (type & XFS_IOLOCK_EXCL)
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mutex_unlock(&VFS_I(ip)->i_mutex);
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}
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static inline void
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xfs_rw_ilock_demote(
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struct xfs_inode *ip,
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int type)
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{
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xfs_ilock_demote(ip, type);
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if (type & XFS_IOLOCK_EXCL)
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mutex_unlock(&VFS_I(ip)->i_mutex);
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}
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/*
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* xfs_iozero clears the specified range supplied via the page cache (except in
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* the DAX case). Writes through the page cache will allocate blocks over holes,
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* though the callers usually map the holes first and avoid them. If a block is
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* not completely zeroed, then it will be read from disk before being partially
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* zeroed.
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*
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* In the DAX case, we can just directly write to the underlying pages. This
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* will not allocate blocks, but will avoid holes and unwritten extents and so
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* not do unnecessary work.
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*/
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int
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xfs_iozero(
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struct xfs_inode *ip, /* inode */
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loff_t pos, /* offset in file */
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size_t count) /* size of data to zero */
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{
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struct page *page;
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struct address_space *mapping;
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int status = 0;
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mapping = VFS_I(ip)->i_mapping;
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do {
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unsigned offset, bytes;
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void *fsdata;
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offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
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bytes = PAGE_CACHE_SIZE - offset;
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if (bytes > count)
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bytes = count;
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if (IS_DAX(VFS_I(ip))) {
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status = dax_zero_page_range(VFS_I(ip), pos, bytes,
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xfs_get_blocks_direct);
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if (status)
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break;
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} else {
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status = pagecache_write_begin(NULL, mapping, pos, bytes,
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AOP_FLAG_UNINTERRUPTIBLE,
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&page, &fsdata);
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if (status)
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break;
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zero_user(page, offset, bytes);
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status = pagecache_write_end(NULL, mapping, pos, bytes,
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bytes, page, fsdata);
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WARN_ON(status <= 0); /* can't return less than zero! */
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status = 0;
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}
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pos += bytes;
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count -= bytes;
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} while (count);
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return status;
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}
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int
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xfs_update_prealloc_flags(
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struct xfs_inode *ip,
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enum xfs_prealloc_flags flags)
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{
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struct xfs_trans *tp;
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int error;
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tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
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error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
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if (error) {
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xfs_trans_cancel(tp);
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return error;
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}
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
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if (!(flags & XFS_PREALLOC_INVISIBLE)) {
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ip->i_d.di_mode &= ~S_ISUID;
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if (ip->i_d.di_mode & S_IXGRP)
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ip->i_d.di_mode &= ~S_ISGID;
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xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
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}
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if (flags & XFS_PREALLOC_SET)
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ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
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if (flags & XFS_PREALLOC_CLEAR)
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ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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if (flags & XFS_PREALLOC_SYNC)
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xfs_trans_set_sync(tp);
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return xfs_trans_commit(tp);
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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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struct xfs_mount *mp = ip->i_mount;
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xfs_lsn_t lsn = 0;
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trace_xfs_dir_fsync(ip);
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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if (xfs_ipincount(ip))
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lsn = ip->i_itemp->ili_last_lsn;
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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if (!lsn)
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return 0;
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return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
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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 inode *inode = file->f_mapping->host;
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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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int error = 0;
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int log_flushed = 0;
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xfs_lsn_t lsn = 0;
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trace_xfs_file_fsync(ip);
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error = filemap_write_and_wait_range(inode->i_mapping, start, end);
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if (error)
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return error;
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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xfs_iflags_clear(ip, XFS_ITRUNCATED);
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if (mp->m_flags & XFS_MOUNT_BARRIER) {
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/*
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* If we have an RT and/or log subvolume we need to make sure
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* to flush the write cache the device used for file data
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* first. This is to ensure newly written file data make
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* it to disk before logging the new inode size in case of
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* an extending write.
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*/
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if (XFS_IS_REALTIME_INODE(ip))
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xfs_blkdev_issue_flush(mp->m_rtdev_targp);
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else if (mp->m_logdev_targp != mp->m_ddev_targp)
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xfs_blkdev_issue_flush(mp->m_ddev_targp);
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}
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/*
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* All metadata updates are logged, which means that we just have
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* to flush the log up to the latest LSN that touched the inode.
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*/
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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if (xfs_ipincount(ip)) {
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if (!datasync ||
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(ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
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lsn = ip->i_itemp->ili_last_lsn;
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}
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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if (lsn)
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error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
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/*
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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 ((mp->m_flags & XFS_MOUNT_BARRIER) &&
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mp->m_logdev_targp == mp->m_ddev_targp &&
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!XFS_IS_REALTIME_INODE(ip) &&
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!log_flushed)
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xfs_blkdev_issue_flush(mp->m_ddev_targp);
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return error;
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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 file *file = iocb->ki_filp;
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struct inode *inode = file->f_mapping->host;
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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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size_t size = iov_iter_count(to);
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ssize_t ret = 0;
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int ioflags = 0;
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xfs_fsize_t n;
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loff_t pos = iocb->ki_pos;
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XFS_STATS_INC(xs_read_calls);
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if (unlikely(iocb->ki_flags & IOCB_DIRECT))
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ioflags |= XFS_IO_ISDIRECT;
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if (file->f_mode & FMODE_NOCMTIME)
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ioflags |= XFS_IO_INVIS;
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if ((ioflags & XFS_IO_ISDIRECT) && !IS_DAX(inode)) {
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xfs_buftarg_t *target =
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XFS_IS_REALTIME_INODE(ip) ?
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mp->m_rtdev_targp : mp->m_ddev_targp;
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/* DIO must be aligned to device logical sector size */
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if ((pos | size) & target->bt_logical_sectormask) {
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if (pos == i_size_read(inode))
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return 0;
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return -EINVAL;
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}
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}
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n = mp->m_super->s_maxbytes - pos;
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if (n <= 0 || size == 0)
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return 0;
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if (n < size)
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size = n;
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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/*
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* Locking is a bit tricky here. If we take an exclusive lock
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* for direct IO, we effectively serialise all new concurrent
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* read IO to this file and block it behind IO that is currently in
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* progress because IO in progress holds the IO lock shared. We only
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* need to hold the lock exclusive to blow away the page cache, so
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* only take lock exclusively if the page cache needs invalidation.
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* This allows the normal direct IO case of no page cache pages to
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* proceeed concurrently without serialisation.
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*/
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xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
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if ((ioflags & XFS_IO_ISDIRECT) && inode->i_mapping->nrpages) {
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
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if (inode->i_mapping->nrpages) {
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ret = filemap_write_and_wait_range(
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VFS_I(ip)->i_mapping,
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pos, pos + size - 1);
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if (ret) {
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xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
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return ret;
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}
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/*
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* Invalidate whole pages. This can return an error if
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* we fail to invalidate a page, but this should never
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* happen on XFS. Warn if it does fail.
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*/
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ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
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pos >> PAGE_CACHE_SHIFT,
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(pos + size - 1) >> PAGE_CACHE_SHIFT);
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WARN_ON_ONCE(ret);
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ret = 0;
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}
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xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
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}
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trace_xfs_file_read(ip, size, pos, ioflags);
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ret = generic_file_read_iter(iocb, to);
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if (ret > 0)
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XFS_STATS_ADD(xs_read_bytes, ret);
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
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}
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STATIC ssize_t
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xfs_file_splice_read(
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struct file *infilp,
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loff_t *ppos,
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struct pipe_inode_info *pipe,
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size_t count,
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unsigned int flags)
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{
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struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
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int ioflags = 0;
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ssize_t ret;
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XFS_STATS_INC(xs_read_calls);
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if (infilp->f_mode & FMODE_NOCMTIME)
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ioflags |= XFS_IO_INVIS;
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if (XFS_FORCED_SHUTDOWN(ip->i_mount))
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return -EIO;
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xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
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trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
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/* for dax, we need to avoid the page cache */
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if (IS_DAX(VFS_I(ip)))
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ret = default_file_splice_read(infilp, ppos, pipe, count, flags);
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else
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ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
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if (ret > 0)
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XFS_STATS_ADD(xs_read_bytes, ret);
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xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
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return ret;
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}
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/*
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* This routine is called to handle zeroing any space in the last block of the
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* file that is beyond the EOF. We do this since the size is being increased
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* without writing anything to that block and we don't want to read the
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* garbage on the disk.
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*/
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STATIC int /* error (positive) */
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xfs_zero_last_block(
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struct xfs_inode *ip,
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xfs_fsize_t offset,
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xfs_fsize_t isize,
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bool *did_zeroing)
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{
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struct xfs_mount *mp = ip->i_mount;
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xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
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int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
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int zero_len;
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int nimaps = 1;
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int error = 0;
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struct xfs_bmbt_irec imap;
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
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xfs_iunlock(ip, XFS_ILOCK_EXCL);
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if (error)
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return error;
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ASSERT(nimaps > 0);
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/*
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* If the block underlying isize is just a hole, then there
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* is nothing to zero.
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*/
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if (imap.br_startblock == HOLESTARTBLOCK)
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return 0;
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zero_len = mp->m_sb.sb_blocksize - zero_offset;
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if (isize + zero_len > offset)
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zero_len = offset - isize;
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*did_zeroing = true;
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return xfs_iozero(ip, isize, zero_len);
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}
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/*
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* Zero any on disk space between the current EOF and the new, larger EOF.
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*
|
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* This handles the normal case of zeroing the remainder of the last block in
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* the file and the unusual case of zeroing blocks out beyond the size of the
|
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* file. This second case only happens with fixed size extents and when the
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* system crashes before the inode size was updated but after blocks were
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* allocated.
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*
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* Expects the iolock to be held exclusive, and will take the ilock internally.
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*/
|
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int /* error (positive) */
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xfs_zero_eof(
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struct xfs_inode *ip,
|
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xfs_off_t offset, /* starting I/O offset */
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xfs_fsize_t isize, /* current inode size */
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bool *did_zeroing)
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{
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struct xfs_mount *mp = ip->i_mount;
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xfs_fileoff_t start_zero_fsb;
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xfs_fileoff_t end_zero_fsb;
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xfs_fileoff_t zero_count_fsb;
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xfs_fileoff_t last_fsb;
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xfs_fileoff_t zero_off;
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|
xfs_fsize_t zero_len;
|
|
int nimaps;
|
|
int error = 0;
|
|
struct xfs_bmbt_irec imap;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
|
|
ASSERT(offset > isize);
|
|
|
|
/*
|
|
* First handle zeroing the block on which isize resides.
|
|
*
|
|
* We only zero a part of that block so it is handled specially.
|
|
*/
|
|
if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
|
|
error = xfs_zero_last_block(ip, offset, isize, did_zeroing);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Calculate the range between the new size and the old where blocks
|
|
* needing to be zeroed may exist.
|
|
*
|
|
* To get the block where the last byte in the file currently resides,
|
|
* we need to subtract one from the size and truncate back to a block
|
|
* boundary. We subtract 1 in case the size is exactly on a block
|
|
* boundary.
|
|
*/
|
|
last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
|
|
start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
|
|
end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
|
|
ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
|
|
if (last_fsb == end_zero_fsb) {
|
|
/*
|
|
* The size was only incremented on its last block.
|
|
* We took care of that above, so just return.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
ASSERT(start_zero_fsb <= end_zero_fsb);
|
|
while (start_zero_fsb <= end_zero_fsb) {
|
|
nimaps = 1;
|
|
zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
|
|
&imap, &nimaps, 0);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
if (error)
|
|
return error;
|
|
|
|
ASSERT(nimaps > 0);
|
|
|
|
if (imap.br_state == XFS_EXT_UNWRITTEN ||
|
|
imap.br_startblock == HOLESTARTBLOCK) {
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* There are blocks we need to zero.
|
|
*/
|
|
zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
|
|
zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
|
|
|
|
if ((zero_off + zero_len) > offset)
|
|
zero_len = offset - zero_off;
|
|
|
|
error = xfs_iozero(ip, zero_off, zero_len);
|
|
if (error)
|
|
return error;
|
|
|
|
*did_zeroing = true;
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
restart:
|
|
error = generic_write_checks(iocb, from);
|
|
if (error <= 0)
|
|
return error;
|
|
|
|
error = xfs_break_layouts(inode, iolock, true);
|
|
if (error)
|
|
return error;
|
|
|
|
/* For changing security info in file_remove_privs() we need i_mutex */
|
|
if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_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)) {
|
|
bool zero = false;
|
|
|
|
spin_unlock(&ip->i_flags_lock);
|
|
if (*iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_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);
|
|
goto restart;
|
|
}
|
|
error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
loff_t pos = iocb->ki_pos;
|
|
loff_t end;
|
|
struct iov_iter data;
|
|
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 (!IS_DAX(inode) && ((pos | count) & target->bt_logical_sectormask))
|
|
return -EINVAL;
|
|
|
|
/* "unaligned" here means not aligned to a filesystem block */
|
|
if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
|
|
unaligned_io = 1;
|
|
|
|
/*
|
|
* We don't need to take an exclusive lock unless there page cache needs
|
|
* to be invalidated or unaligned IO is being executed. We don't need to
|
|
* consider the EOF extension case here because
|
|
* xfs_file_aio_write_checks() will relock the inode as necessary for
|
|
* EOF zeroing cases and fill out the new inode size as appropriate.
|
|
*/
|
|
if (unaligned_io || mapping->nrpages)
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
else
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
/*
|
|
* Recheck if there are cached pages that need invalidate after we got
|
|
* the iolock to protect against other threads adding new pages while
|
|
* we were waiting for the iolock.
|
|
*/
|
|
if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, iolock);
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, iolock);
|
|
}
|
|
|
|
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
count = iov_iter_count(from);
|
|
pos = iocb->ki_pos;
|
|
end = pos + count - 1;
|
|
|
|
if (mapping->nrpages) {
|
|
ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
|
|
pos, end);
|
|
if (ret)
|
|
goto out;
|
|
/*
|
|
* Invalidate whole pages. This can return an error if
|
|
* we fail to invalidate a page, but this should never
|
|
* happen on XFS. Warn if it does fail.
|
|
*/
|
|
ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
|
|
pos >> PAGE_CACHE_SHIFT,
|
|
end >> PAGE_CACHE_SHIFT);
|
|
WARN_ON_ONCE(ret);
|
|
ret = 0;
|
|
}
|
|
|
|
/*
|
|
* If we are doing unaligned IO, wait for all other IO to drain,
|
|
* otherwise demote the lock if we had to flush cached pages
|
|
*/
|
|
if (unaligned_io)
|
|
inode_dio_wait(inode);
|
|
else if (iolock == XFS_IOLOCK_EXCL) {
|
|
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
}
|
|
|
|
trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
|
|
|
|
data = *from;
|
|
ret = mapping->a_ops->direct_IO(iocb, &data, pos);
|
|
|
|
/* see generic_file_direct_write() for why this is necessary */
|
|
if (mapping->nrpages) {
|
|
invalidate_inode_pages2_range(mapping,
|
|
pos >> PAGE_CACHE_SHIFT,
|
|
end >> PAGE_CACHE_SHIFT);
|
|
}
|
|
|
|
if (ret > 0) {
|
|
pos += ret;
|
|
iov_iter_advance(from, ret);
|
|
iocb->ki_pos = pos;
|
|
}
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
|
|
/*
|
|
* No fallback to buffered IO on errors for XFS. DAX can result in
|
|
* partial writes, but direct IO will either complete fully or fail.
|
|
*/
|
|
ASSERT(ret < 0 || ret == count || IS_DAX(VFS_I(ip)));
|
|
return ret;
|
|
}
|
|
|
|
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 = XFS_IOLOCK_EXCL;
|
|
|
|
xfs_rw_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);
|
|
|
|
write_retry:
|
|
trace_xfs_file_buffered_write(ip, iov_iter_count(from),
|
|
iocb->ki_pos, 0);
|
|
ret = generic_perform_write(file, from, iocb->ki_pos);
|
|
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) {
|
|
enospc = xfs_inode_free_quota_eofblocks(ip);
|
|
if (enospc)
|
|
goto write_retry;
|
|
} else if (ret == -ENOSPC && !enospc) {
|
|
struct xfs_eofblocks eofb = {0};
|
|
|
|
enospc = 1;
|
|
xfs_flush_inodes(ip->i_mount);
|
|
eofb.eof_scan_owner = ip->i_ino; /* for locking */
|
|
eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
|
|
xfs_icache_free_eofblocks(ip->i_mount, &eofb);
|
|
goto write_retry;
|
|
}
|
|
|
|
current->backing_dev_info = NULL;
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
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(xs_write_calls);
|
|
|
|
if (ocount == 0)
|
|
return 0;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
return -EIO;
|
|
|
|
if ((iocb->ki_flags & IOCB_DIRECT) || IS_DAX(inode))
|
|
ret = xfs_file_dio_aio_write(iocb, from);
|
|
else
|
|
ret = xfs_file_buffered_aio_write(iocb, from);
|
|
|
|
if (ret > 0) {
|
|
ssize_t err;
|
|
|
|
XFS_STATS_ADD(xs_write_bytes, ret);
|
|
|
|
/* Handle various SYNC-type writes */
|
|
err = generic_write_sync(file, iocb->ki_pos - ret, ret);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#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)
|
|
|
|
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 = 0;
|
|
|
|
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, false);
|
|
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 blksize_mask = (1 << inode->i_blkbits) - 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 blksize_mask = (1 << inode->i_blkbits) - 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 = 1;
|
|
} 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
|
|
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_setattr_size(ip, &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;
|
|
}
|
|
|
|
|
|
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;
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_dir_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int mode;
|
|
int error;
|
|
|
|
error = xfs_file_open(inode, file);
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* If there are any blocks, read-ahead block 0 as we're almost
|
|
* certain to have the next operation be a read there.
|
|
*/
|
|
mode = xfs_ilock_data_map_shared(ip);
|
|
if (ip->i_d.di_nextents > 0)
|
|
xfs_dir3_data_readahead(ip, 0, -1);
|
|
xfs_iunlock(ip, mode);
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_release(
|
|
struct inode *inode,
|
|
struct file *filp)
|
|
{
|
|
return xfs_release(XFS_I(inode));
|
|
}
|
|
|
|
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, 32768, ip->i_d.di_size);
|
|
|
|
return xfs_readdir(ip, ctx, bufsize);
|
|
}
|
|
|
|
/*
|
|
* This type is designed to indicate the type of offset we would like
|
|
* to search from page cache for xfs_seek_hole_data().
|
|
*/
|
|
enum {
|
|
HOLE_OFF = 0,
|
|
DATA_OFF,
|
|
};
|
|
|
|
/*
|
|
* Lookup the desired type of offset from the given page.
|
|
*
|
|
* On success, return true and the offset argument will point to the
|
|
* start of the region that was found. Otherwise this function will
|
|
* return false and keep the offset argument unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_lookup_buffer_offset(
|
|
struct page *page,
|
|
loff_t *offset,
|
|
unsigned int type)
|
|
{
|
|
loff_t lastoff = page_offset(page);
|
|
bool found = false;
|
|
struct buffer_head *bh, *head;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
/*
|
|
* Unwritten extents that have data in the page
|
|
* cache covering them can be identified by the
|
|
* BH_Unwritten state flag. Pages with multiple
|
|
* buffers might have a mix of holes, data and
|
|
* unwritten extents - any buffer with valid
|
|
* data in it should have BH_Uptodate flag set
|
|
* on it.
|
|
*/
|
|
if (buffer_unwritten(bh) ||
|
|
buffer_uptodate(bh)) {
|
|
if (type == DATA_OFF)
|
|
found = true;
|
|
} else {
|
|
if (type == HOLE_OFF)
|
|
found = true;
|
|
}
|
|
|
|
if (found) {
|
|
*offset = lastoff;
|
|
break;
|
|
}
|
|
lastoff += bh->b_size;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* This routine is called to find out and return a data or hole offset
|
|
* from the page cache for unwritten extents according to the desired
|
|
* type for xfs_seek_hole_data().
|
|
*
|
|
* The argument offset is used to tell where we start to search from the
|
|
* page cache. Map is used to figure out the end points of the range to
|
|
* lookup pages.
|
|
*
|
|
* Return true if the desired type of offset was found, and the argument
|
|
* offset is filled with that address. Otherwise, return false and keep
|
|
* offset unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_find_get_desired_pgoff(
|
|
struct inode *inode,
|
|
struct xfs_bmbt_irec *map,
|
|
unsigned int type,
|
|
loff_t *offset)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct pagevec pvec;
|
|
pgoff_t index;
|
|
pgoff_t end;
|
|
loff_t endoff;
|
|
loff_t startoff = *offset;
|
|
loff_t lastoff = startoff;
|
|
bool found = false;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
index = startoff >> PAGE_CACHE_SHIFT;
|
|
endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
|
|
end = endoff >> PAGE_CACHE_SHIFT;
|
|
do {
|
|
int want;
|
|
unsigned nr_pages;
|
|
unsigned int i;
|
|
|
|
want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
|
|
nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
|
|
want);
|
|
/*
|
|
* No page mapped into given range. If we are searching holes
|
|
* and if this is the first time we got into the loop, it means
|
|
* that the given offset is landed in a hole, return it.
|
|
*
|
|
* If we have already stepped through some block buffers to find
|
|
* holes but they all contains data. In this case, the last
|
|
* offset is already updated and pointed to the end of the last
|
|
* mapped page, if it does not reach the endpoint to search,
|
|
* that means there should be a hole between them.
|
|
*/
|
|
if (nr_pages == 0) {
|
|
/* Data search found nothing */
|
|
if (type == DATA_OFF)
|
|
break;
|
|
|
|
ASSERT(type == HOLE_OFF);
|
|
if (lastoff == startoff || lastoff < endoff) {
|
|
found = true;
|
|
*offset = lastoff;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At lease we found one page. If this is the first time we
|
|
* step into the loop, and if the first page index offset is
|
|
* greater than the given search offset, a hole was found.
|
|
*/
|
|
if (type == HOLE_OFF && lastoff == startoff &&
|
|
lastoff < page_offset(pvec.pages[0])) {
|
|
found = true;
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
loff_t b_offset;
|
|
|
|
/*
|
|
* At this point, the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL),
|
|
* or even swizzled back from swapper_space to tmpfs
|
|
* file mapping. However, page->index will not change
|
|
* because we have a reference on the page.
|
|
*
|
|
* Searching done if the page index is out of range.
|
|
* If the current offset is not reaches the end of
|
|
* the specified search range, there should be a hole
|
|
* between them.
|
|
*/
|
|
if (page->index > end) {
|
|
if (type == HOLE_OFF && lastoff < endoff) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
lock_page(page);
|
|
/*
|
|
* Page truncated or invalidated(page->mapping == NULL).
|
|
* We can freely skip it and proceed to check the next
|
|
* page.
|
|
*/
|
|
if (unlikely(page->mapping != inode->i_mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!page_has_buffers(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
found = xfs_lookup_buffer_offset(page, &b_offset, type);
|
|
if (found) {
|
|
/*
|
|
* The found offset may be less than the start
|
|
* point to search if this is the first time to
|
|
* come here.
|
|
*/
|
|
*offset = max_t(loff_t, startoff, b_offset);
|
|
unlock_page(page);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We either searching data but nothing was found, or
|
|
* searching hole but found a data buffer. In either
|
|
* case, probably the next page contains the desired
|
|
* things, update the last offset to it so.
|
|
*/
|
|
lastoff = page_offset(page) + PAGE_SIZE;
|
|
unlock_page(page);
|
|
}
|
|
|
|
/*
|
|
* The number of returned pages less than our desired, search
|
|
* done. In this case, nothing was found for searching data,
|
|
* but we found a hole behind the last offset.
|
|
*/
|
|
if (nr_pages < want) {
|
|
if (type == HOLE_OFF) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
index = pvec.pages[i - 1]->index + 1;
|
|
pagevec_release(&pvec);
|
|
} while (index <= end);
|
|
|
|
out:
|
|
pagevec_release(&pvec);
|
|
return found;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_seek_hole_data(
|
|
struct file *file,
|
|
loff_t start,
|
|
int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
loff_t uninitialized_var(offset);
|
|
xfs_fsize_t isize;
|
|
xfs_fileoff_t fsbno;
|
|
xfs_filblks_t end;
|
|
uint lock;
|
|
int error;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
lock = xfs_ilock_data_map_shared(ip);
|
|
|
|
isize = i_size_read(inode);
|
|
if (start >= isize) {
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Try to read extents from the first block indicated
|
|
* by fsbno to the end block of the file.
|
|
*/
|
|
fsbno = XFS_B_TO_FSBT(mp, start);
|
|
end = XFS_B_TO_FSB(mp, isize);
|
|
|
|
for (;;) {
|
|
struct xfs_bmbt_irec map[2];
|
|
int nmap = 2;
|
|
unsigned int i;
|
|
|
|
error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
|
|
XFS_BMAPI_ENTIRE);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* No extents at given offset, must be beyond EOF */
|
|
if (nmap == 0) {
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
for (i = 0; i < nmap; i++) {
|
|
offset = max_t(loff_t, start,
|
|
XFS_FSB_TO_B(mp, map[i].br_startoff));
|
|
|
|
/* Landed in the hole we wanted? */
|
|
if (whence == SEEK_HOLE &&
|
|
map[i].br_startblock == HOLESTARTBLOCK)
|
|
goto out;
|
|
|
|
/* Landed in the data extent we wanted? */
|
|
if (whence == SEEK_DATA &&
|
|
(map[i].br_startblock == DELAYSTARTBLOCK ||
|
|
(map[i].br_state == XFS_EXT_NORM &&
|
|
!isnullstartblock(map[i].br_startblock))))
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search
|
|
* for hole or data from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
whence == SEEK_HOLE ? HOLE_OFF : DATA_OFF,
|
|
&offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We only received one extent out of the two requested. This
|
|
* means we've hit EOF and didn't find what we are looking for.
|
|
*/
|
|
if (nmap == 1) {
|
|
/*
|
|
* If we were looking for a hole, set offset to
|
|
* the end of the file (i.e., there is an implicit
|
|
* hole at the end of any file).
|
|
*/
|
|
if (whence == SEEK_HOLE) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
/*
|
|
* If we were looking for data, it's nowhere to be found
|
|
*/
|
|
ASSERT(whence == SEEK_DATA);
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Nothing was found, proceed to the next round of search
|
|
* if the next reading offset is not at or beyond EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
if (whence == SEEK_HOLE) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
ASSERT(whence == SEEK_DATA);
|
|
error = -ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/*
|
|
* If at this point we have found the hole we wanted, the returned
|
|
* offset may be bigger than the file size as it may be aligned to
|
|
* page boundary for unwritten extents. We need to deal with this
|
|
* situation in particular.
|
|
*/
|
|
if (whence == SEEK_HOLE)
|
|
offset = min_t(loff_t, offset, isize);
|
|
offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, lock);
|
|
|
|
if (error)
|
|
return error;
|
|
return offset;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_file_llseek(
|
|
struct file *file,
|
|
loff_t offset,
|
|
int whence)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_END:
|
|
case SEEK_CUR:
|
|
case SEEK_SET:
|
|
return generic_file_llseek(file, offset, whence);
|
|
case SEEK_HOLE:
|
|
case SEEK_DATA:
|
|
return xfs_seek_hole_data(file, offset, whence);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Locking for serialisation of IO during page faults. This results in a lock
|
|
* ordering of:
|
|
*
|
|
* mmap_sem (MM)
|
|
* sb_start_pagefault(vfs, freeze)
|
|
* i_mmap_lock (XFS - truncate serialisation)
|
|
* page_lock (MM)
|
|
* i_lock (XFS - extent map serialisation)
|
|
*/
|
|
|
|
/*
|
|
* mmap()d file has taken write protection fault and is being made writable. We
|
|
* can set the page state up correctly for a writable page, which means we can
|
|
* do correct delalloc accounting (ENOSPC checking!) and unwritten extent
|
|
* mapping.
|
|
*/
|
|
STATIC int
|
|
xfs_filemap_page_mkwrite(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
struct inode *inode = file_inode(vma->vm_file);
|
|
int ret;
|
|
|
|
trace_xfs_filemap_page_mkwrite(XFS_I(inode));
|
|
|
|
sb_start_pagefault(inode->i_sb);
|
|
file_update_time(vma->vm_file);
|
|
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
|
|
if (IS_DAX(inode)) {
|
|
ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_direct,
|
|
xfs_end_io_dax_write);
|
|
} else {
|
|
ret = __block_page_mkwrite(vma, vmf, xfs_get_blocks);
|
|
ret = block_page_mkwrite_return(ret);
|
|
}
|
|
|
|
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
sb_end_pagefault(inode->i_sb);
|
|
|
|
return ret;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_filemap_fault(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
struct inode *inode = file_inode(vma->vm_file);
|
|
int ret;
|
|
|
|
trace_xfs_filemap_fault(XFS_I(inode));
|
|
|
|
/* DAX can shortcut the normal fault path on write faults! */
|
|
if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode))
|
|
return xfs_filemap_page_mkwrite(vma, vmf);
|
|
|
|
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
if (IS_DAX(inode)) {
|
|
/*
|
|
* we do not want to trigger unwritten extent conversion on read
|
|
* faults - that is unnecessary overhead and would also require
|
|
* changes to xfs_get_blocks_direct() to map unwritten extent
|
|
* ioend for conversion on read-only mappings.
|
|
*/
|
|
ret = __dax_fault(vma, vmf, xfs_get_blocks_direct, NULL);
|
|
} else
|
|
ret = filemap_fault(vma, vmf);
|
|
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops = {
|
|
.fault = xfs_filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.page_mkwrite = xfs_filemap_page_mkwrite,
|
|
};
|
|
|
|
STATIC int
|
|
xfs_file_mmap(
|
|
struct file *filp,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
file_accessed(filp);
|
|
vma->vm_ops = &xfs_file_vm_ops;
|
|
if (IS_DAX(file_inode(filp)))
|
|
vma->vm_flags |= VM_MIXEDMAP;
|
|
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,
|
|
.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,
|
|
.fallocate = xfs_file_fallocate,
|
|
};
|
|
|
|
const struct file_operations xfs_dir_file_operations = {
|
|
.open = xfs_dir_open,
|
|
.read = generic_read_dir,
|
|
.iterate = 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,
|
|
};
|