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![Christoph Hellwig](/assets/img/avatar_default.png)
With all the size field updates out of the way xfs_file_aio_write can be further simplified by pushing all iolock handling into xfs_file_dio_aio_write and xfs_file_buffered_aio_write and using the generic generic_write_sync helper for synchronous writes. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
1096 lines
29 KiB
C
1096 lines
29 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_bit.h"
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#include "xfs_log.h"
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#include "xfs_inum.h"
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#include "xfs_sb.h"
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#include "xfs_ag.h"
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#include "xfs_trans.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_alloc.h"
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#include "xfs_dinode.h"
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#include "xfs_inode.h"
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#include "xfs_inode_item.h"
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#include "xfs_bmap.h"
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#include "xfs_error.h"
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#include "xfs_vnodeops.h"
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#include "xfs_da_btree.h"
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#include "xfs_ioctl.h"
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#include "xfs_trace.h"
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#include <linux/dcache.h>
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#include <linux/falloc.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
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*
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* xfs_iozero clears the specified range of buffer supplied,
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* and marks all the affected blocks as valid and modified. If
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* an affected block is not allocated, it will be allocated. If
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* an affected block is not completely overwritten, and is not
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* valid before the operation, it will be read from disk before
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* being partially zeroed.
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*/
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STATIC 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;
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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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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, bytes,
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page, fsdata);
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WARN_ON(status <= 0); /* can't return less than zero! */
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pos += bytes;
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count -= bytes;
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status = 0;
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} while (count);
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return (-status);
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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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struct xfs_trans *tp;
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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 -XFS_ERROR(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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* We always need to make sure that the required inode state is safe on
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* disk. The inode might be clean but we still might need to force the
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* log because of committed transactions that haven't hit the disk yet.
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* Likewise, there could be unflushed non-transactional changes to the
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* inode core that have to go to disk and this requires us to issue
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* a synchronous transaction to capture these changes correctly.
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*
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* This code relies on the assumption that if the i_update_core field
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* of the inode is clear and the inode is unpinned then it is clean
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* and no action is required.
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*/
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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/*
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* First check if the VFS inode is marked dirty. All the dirtying
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* of non-transactional updates do not go through mark_inode_dirty*,
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* which allows us to distinguish between pure timestamp updates
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* and i_size updates which need to be caught for fdatasync.
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* After that also check for the dirty state in the XFS inode, which
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* might gets cleared when the inode gets written out via the AIL
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* or xfs_iflush_cluster.
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*/
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if (((inode->i_state & I_DIRTY_DATASYNC) ||
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((inode->i_state & I_DIRTY_SYNC) && !datasync)) &&
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ip->i_update_core) {
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/*
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* Kick off a transaction to log the inode core to get the
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* updates. The sync transaction will also force the log.
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*/
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
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error = xfs_trans_reserve(tp, 0,
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XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
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if (error) {
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xfs_trans_cancel(tp, 0);
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return -error;
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}
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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/*
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* Note - it's possible that we might have pushed ourselves out
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* of the way during trans_reserve which would flush the inode.
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* But there's no guarantee that the inode buffer has actually
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* gone out yet (it's delwri). Plus the buffer could be pinned
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* anyway if it's part of an inode in another recent
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* transaction. So we play it safe and fire off the
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* transaction anyway.
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*/
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xfs_trans_ijoin(tp, ip, 0);
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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error = xfs_trans_commit(tp, 0);
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lsn = ip->i_itemp->ili_last_lsn;
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xfs_iunlock(ip, XFS_ILOCK_EXCL);
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} else {
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/*
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* Timestamps/size haven't changed since last inode flush or
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* inode transaction commit. That means either nothing got
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* written or a transaction committed which caught the updates.
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* If the latter happened and the transaction hasn't hit the
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* disk yet, the inode will be still be pinned. If it is,
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* force the log.
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*/
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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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}
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if (!error && 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_aio_read(
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struct kiocb *iocb,
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const struct iovec *iovp,
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unsigned long nr_segs,
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loff_t pos)
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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 = 0;
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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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unsigned long seg;
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XFS_STATS_INC(xs_read_calls);
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BUG_ON(iocb->ki_pos != pos);
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if (unlikely(file->f_flags & O_DIRECT))
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ioflags |= IO_ISDIRECT;
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if (file->f_mode & FMODE_NOCMTIME)
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ioflags |= IO_INVIS;
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/* START copy & waste from filemap.c */
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for (seg = 0; seg < nr_segs; seg++) {
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const struct iovec *iv = &iovp[seg];
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/*
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* If any segment has a negative length, or the cumulative
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* length ever wraps negative then return -EINVAL.
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*/
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size += iv->iov_len;
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if (unlikely((ssize_t)(size|iv->iov_len) < 0))
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return XFS_ERROR(-EINVAL);
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}
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/* END copy & waste from filemap.c */
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if (unlikely(ioflags & IO_ISDIRECT)) {
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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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if ((iocb->ki_pos & target->bt_smask) ||
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(size & target->bt_smask)) {
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if (iocb->ki_pos == i_size_read(inode))
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return 0;
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return -XFS_ERROR(EINVAL);
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}
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}
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n = XFS_MAXIOFFSET(mp) - iocb->ki_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 & 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 = -xfs_flushinval_pages(ip,
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(iocb->ki_pos & PAGE_CACHE_MASK),
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-1, FI_REMAPF_LOCKED);
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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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xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
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}
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trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
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ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos);
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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 |= 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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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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* xfs_file_splice_write() does not use xfs_rw_ilock() because
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* generic_file_splice_write() takes the i_mutex itself. This, in theory,
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* couuld cause lock inversions between the aio_write path and the splice path
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* if someone is doing concurrent splice(2) based writes and write(2) based
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* writes to the same inode. The only real way to fix this is to re-implement
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* the generic code here with correct locking orders.
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*/
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STATIC ssize_t
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xfs_file_splice_write(
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struct pipe_inode_info *pipe,
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struct file *outfilp,
|
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loff_t *ppos,
|
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size_t count,
|
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unsigned int flags)
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{
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struct inode *inode = outfilp->f_mapping->host;
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struct xfs_inode *ip = XFS_I(inode);
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int ioflags = 0;
|
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ssize_t ret;
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XFS_STATS_INC(xs_write_calls);
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if (outfilp->f_mode & FMODE_NOCMTIME)
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ioflags |= IO_INVIS;
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if (XFS_FORCED_SHUTDOWN(ip->i_mount))
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return -EIO;
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xfs_ilock(ip, XFS_IOLOCK_EXCL);
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trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
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ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
|
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if (ret > 0)
|
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XFS_STATS_ADD(xs_write_bytes, ret);
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|
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xfs_iunlock(ip, XFS_IOLOCK_EXCL);
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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
|
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* block of the file that is beyond the EOF. We do this since the
|
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* size is being increased without writing anything to that block
|
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* and we don't want anyone to read the garbage on the disk.
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*/
|
|
STATIC int /* error (positive) */
|
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xfs_zero_last_block(
|
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xfs_inode_t *ip,
|
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xfs_fsize_t offset,
|
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xfs_fsize_t isize)
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{
|
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xfs_fileoff_t last_fsb;
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xfs_mount_t *mp = ip->i_mount;
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int nimaps;
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int zero_offset;
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int zero_len;
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int error = 0;
|
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xfs_bmbt_irec_t imap;
|
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|
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ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
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zero_offset = XFS_B_FSB_OFFSET(mp, isize);
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if (zero_offset == 0) {
|
|
/*
|
|
* There are no extra bytes in the last block on disk to
|
|
* zero, so return.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
last_fsb = XFS_B_TO_FSBT(mp, isize);
|
|
nimaps = 1;
|
|
error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
|
|
if (error)
|
|
return error;
|
|
ASSERT(nimaps > 0);
|
|
/*
|
|
* If the block underlying isize is just a hole, then there
|
|
* is nothing to zero.
|
|
*/
|
|
if (imap.br_startblock == HOLESTARTBLOCK) {
|
|
return 0;
|
|
}
|
|
/*
|
|
* Zero the part of the last block beyond the EOF, and write it
|
|
* out sync. We need to drop the ilock while we do this so we
|
|
* don't deadlock when the buffer cache calls back to us.
|
|
*/
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
zero_len = mp->m_sb.sb_blocksize - zero_offset;
|
|
if (isize + zero_len > offset)
|
|
zero_len = offset - isize;
|
|
error = xfs_iozero(ip, isize, zero_len);
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
ASSERT(error >= 0);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Zero any on disk space between the current EOF and the new,
|
|
* larger EOF. This handles the normal case of zeroing the remainder
|
|
* of the last block in the file and the unusual case of zeroing blocks
|
|
* out beyond the size of the file. This second case only happens
|
|
* with fixed size extents and when the system crashes before the inode
|
|
* size was updated but after blocks were allocated. If fill is set,
|
|
* then any holes in the range are filled and zeroed. If not, the holes
|
|
* are left alone as holes.
|
|
*/
|
|
|
|
int /* error (positive) */
|
|
xfs_zero_eof(
|
|
xfs_inode_t *ip,
|
|
xfs_off_t offset, /* starting I/O offset */
|
|
xfs_fsize_t isize) /* current inode size */
|
|
{
|
|
xfs_mount_t *mp = ip->i_mount;
|
|
xfs_fileoff_t start_zero_fsb;
|
|
xfs_fileoff_t end_zero_fsb;
|
|
xfs_fileoff_t zero_count_fsb;
|
|
xfs_fileoff_t last_fsb;
|
|
xfs_fileoff_t zero_off;
|
|
xfs_fsize_t zero_len;
|
|
int nimaps;
|
|
int error = 0;
|
|
xfs_bmbt_irec_t imap;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|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.
|
|
*/
|
|
error = xfs_zero_last_block(ip, offset, isize);
|
|
if (error) {
|
|
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
|
|
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;
|
|
error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
|
|
&imap, &nimaps, 0);
|
|
if (error) {
|
|
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
|
|
return error;
|
|
}
|
|
ASSERT(nimaps > 0);
|
|
|
|
if (imap.br_state == XFS_EXT_UNWRITTEN ||
|
|
imap.br_startblock == HOLESTARTBLOCK) {
|
|
/*
|
|
* This loop handles initializing pages that were
|
|
* partially initialized by the code below this
|
|
* loop. It basically zeroes the part of the page
|
|
* that sits on a hole and sets the page as P_HOLE
|
|
* and calls remapf if it is a mapped file.
|
|
*/
|
|
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.
|
|
* Drop the inode lock while we're doing the I/O.
|
|
* We'll still have the iolock to protect us.
|
|
*/
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
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) {
|
|
goto out_lock;
|
|
}
|
|
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_lock:
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
ASSERT(error >= 0);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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 file *file,
|
|
loff_t *pos,
|
|
size_t *count,
|
|
int *iolock)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int error = 0;
|
|
|
|
xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
|
|
restart:
|
|
error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
|
|
if (error) {
|
|
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
|
|
return error;
|
|
}
|
|
|
|
if (likely(!(file->f_mode & FMODE_NOCMTIME)))
|
|
file_update_time(file);
|
|
|
|
/*
|
|
* 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 involves
|
|
* dropping all locks and relocking to maintain correct locking order.
|
|
* If we do this, restart the function to ensure all checks and values
|
|
* are still valid.
|
|
*/
|
|
if (*pos > i_size_read(inode)) {
|
|
if (*iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
|
|
goto restart;
|
|
}
|
|
error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
|
|
}
|
|
xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
|
|
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.
|
|
*/
|
|
return file_remove_suid(file);
|
|
|
|
}
|
|
|
|
/*
|
|
* 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,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos,
|
|
size_t ocount)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
ssize_t ret = 0;
|
|
size_t count = ocount;
|
|
int unaligned_io = 0;
|
|
int iolock;
|
|
struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
|
|
mp->m_rtdev_targp : mp->m_ddev_targp;
|
|
|
|
if ((pos & target->bt_smask) || (count & target->bt_smask))
|
|
return -XFS_ERROR(EINVAL);
|
|
|
|
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(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (mapping->nrpages) {
|
|
ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
|
|
FI_REMAPF_LOCKED);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
ret = generic_file_direct_write(iocb, iovp,
|
|
&nr_segs, pos, &iocb->ki_pos, count, ocount);
|
|
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
|
|
/* No fallback to buffered IO on errors for XFS. */
|
|
ASSERT(ret < 0 || ret == count);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_buffered_aio_write(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos,
|
|
size_t ocount)
|
|
{
|
|
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;
|
|
size_t count = ocount;
|
|
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* We can write back this queue in page reclaim */
|
|
current->backing_dev_info = mapping->backing_dev_info;
|
|
|
|
write_retry:
|
|
trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
|
|
ret = generic_file_buffered_write(iocb, iovp, nr_segs,
|
|
pos, &iocb->ki_pos, count, ret);
|
|
/*
|
|
* if we just got an ENOSPC, flush the inode now we aren't holding any
|
|
* page locks and retry *once*
|
|
*/
|
|
if (ret == -ENOSPC && !enospc) {
|
|
enospc = 1;
|
|
ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
|
|
if (!ret)
|
|
goto write_retry;
|
|
}
|
|
|
|
current->backing_dev_info = NULL;
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_aio_write(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
size_t ocount = 0;
|
|
|
|
XFS_STATS_INC(xs_write_calls);
|
|
|
|
BUG_ON(iocb->ki_pos != pos);
|
|
|
|
ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (ocount == 0)
|
|
return 0;
|
|
|
|
xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
return -EIO;
|
|
|
|
if (unlikely(file->f_flags & O_DIRECT))
|
|
ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
|
|
else
|
|
ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
|
|
ocount);
|
|
|
|
if (ret > 0) {
|
|
ssize_t err;
|
|
|
|
XFS_STATS_ADD(xs_write_bytes, ret);
|
|
|
|
/* Handle various SYNC-type writes */
|
|
err = generic_write_sync(file, pos, ret);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
STATIC long
|
|
xfs_file_fallocate(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file->f_path.dentry->d_inode;
|
|
long error;
|
|
loff_t new_size = 0;
|
|
xfs_flock64_t bf;
|
|
xfs_inode_t *ip = XFS_I(inode);
|
|
int cmd = XFS_IOC_RESVSP;
|
|
int attr_flags = XFS_ATTR_NOLOCK;
|
|
|
|
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
|
|
return -EOPNOTSUPP;
|
|
|
|
bf.l_whence = 0;
|
|
bf.l_start = offset;
|
|
bf.l_len = len;
|
|
|
|
xfs_ilock(ip, XFS_IOLOCK_EXCL);
|
|
|
|
if (mode & FALLOC_FL_PUNCH_HOLE)
|
|
cmd = XFS_IOC_UNRESVSP;
|
|
|
|
/* check the new inode size is valid before allocating */
|
|
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 (file->f_flags & O_DSYNC)
|
|
attr_flags |= XFS_ATTR_SYNC;
|
|
|
|
error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_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, XFS_ATTR_NOLOCK);
|
|
}
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
|
|
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_map_shared(ip);
|
|
if (ip->i_d.di_nextents > 0)
|
|
xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
|
|
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 *filp,
|
|
void *dirent,
|
|
filldir_t filldir)
|
|
{
|
|
struct inode *inode = filp->f_path.dentry->d_inode;
|
|
xfs_inode_t *ip = XFS_I(inode);
|
|
int error;
|
|
size_t bufsize;
|
|
|
|
/*
|
|
* The Linux API doesn't pass down the total size of the buffer
|
|
* we read into down to the filesystem. With the filldir concept
|
|
* it's not needed for correct information, but the XFS dir2 leaf
|
|
* code wants an estimate of the buffer size to calculate it's
|
|
* readahead window and size the buffers used for mapping to
|
|
* physical blocks.
|
|
*
|
|
* Try to give it an estimate that's good enough, maybe at some
|
|
* point we can change the ->readdir prototype to include the
|
|
* buffer size. For now we use the current glibc buffer size.
|
|
*/
|
|
bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
|
|
|
|
error = xfs_readdir(ip, dirent, bufsize,
|
|
(xfs_off_t *)&filp->f_pos, filldir);
|
|
if (error)
|
|
return -error;
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_mmap(
|
|
struct file *filp,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
vma->vm_ops = &xfs_file_vm_ops;
|
|
vma->vm_flags |= VM_CAN_NONLINEAR;
|
|
|
|
file_accessed(filp);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mmap()d file has taken write protection fault and is being made
|
|
* writable. We can set the page state up correctly for a writable
|
|
* page, which means we can do correct delalloc accounting (ENOSPC
|
|
* checking!) and unwritten extent mapping.
|
|
*/
|
|
STATIC int
|
|
xfs_vm_page_mkwrite(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
return block_page_mkwrite(vma, vmf, xfs_get_blocks);
|
|
}
|
|
|
|
const struct file_operations xfs_file_operations = {
|
|
.llseek = generic_file_llseek,
|
|
.read = do_sync_read,
|
|
.write = do_sync_write,
|
|
.aio_read = xfs_file_aio_read,
|
|
.aio_write = xfs_file_aio_write,
|
|
.splice_read = xfs_file_splice_read,
|
|
.splice_write = xfs_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,
|
|
.readdir = 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,
|
|
};
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops = {
|
|
.fault = filemap_fault,
|
|
.page_mkwrite = xfs_vm_page_mkwrite,
|
|
};
|