mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 23:46:42 +07:00
5166701b36
Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
1491 lines
37 KiB
C
1491 lines
37 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_sb.h"
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#include "xfs_ag.h"
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#include "xfs_mount.h"
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#include "xfs_da_format.h"
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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_dinode.h"
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#include <linux/aio.h>
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#include <linux/dcache.h>
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#include <linux/falloc.h>
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#include <linux/pagevec.h>
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static const struct vm_operations_struct xfs_file_vm_ops;
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/*
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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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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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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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* 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_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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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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ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
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if (ret < 0)
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return ret;
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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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/* 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 -XFS_ERROR(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 & 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, -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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truncate_pagecache_range(VFS_I(ip), pos, -1);
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}
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xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
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}
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trace_xfs_file_read(ip, size, pos, ioflags);
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ret = generic_file_aio_read(iocb, iovp, nr_segs, pos);
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if (ret > 0)
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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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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 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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{
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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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return xfs_iozero(ip, isize, zero_len);
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}
|
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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 */
|
|
xfs_fsize_t isize) /* current inode size */
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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;
|
|
xfs_fileoff_t zero_count_fsb;
|
|
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);
|
|
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;
|
|
|
|
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 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;
|
|
|
|
restart:
|
|
error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* If the offset is beyond the size of the file, we need to zero any
|
|
* blocks that fall between the existing EOF and the start of this
|
|
* 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.
|
|
*/
|
|
if (*pos > i_size_read(inode)) {
|
|
if (*iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, *iolock);
|
|
goto restart;
|
|
}
|
|
error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
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;
|
|
|
|
/* DIO must be aligned to device logical sector size */
|
|
if ((pos | count) & target->bt_logical_sectormask)
|
|
return -XFS_ERROR(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(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (mapping->nrpages) {
|
|
ret = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
|
|
pos, -1);
|
|
if (ret)
|
|
goto out;
|
|
truncate_pagecache_range(VFS_I(ip), pos, -1);
|
|
}
|
|
|
|
/*
|
|
* 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, 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 count)
|
|
{
|
|
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;
|
|
struct iov_iter from;
|
|
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
iov_iter_init(&from, iovp, nr_segs, count, 0);
|
|
/* 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_perform_write(file, &from, pos);
|
|
if (likely(ret >= 0))
|
|
iocb->ki_pos = pos + ret;
|
|
/*
|
|
* If we just got an ENOSPC, try to write back all dirty inodes to
|
|
* convert delalloc space to free up some of the excess reserved
|
|
* metadata space.
|
|
*/
|
|
if (ret == -ENOSPC && !enospc) {
|
|
enospc = 1;
|
|
xfs_flush_inodes(ip->i_mount);
|
|
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;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
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, iocb->ki_pos - ret, ret);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
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);
|
|
struct xfs_trans *tp;
|
|
long error;
|
|
loff_t new_size = 0;
|
|
|
|
if (!S_ISREG(inode->i_mode))
|
|
return -EINVAL;
|
|
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
|
|
FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
|
|
return -EOPNOTSUPP;
|
|
|
|
xfs_ilock(ip, XFS_IOLOCK_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;
|
|
}
|
|
|
|
ASSERT(offset + len < i_size_read(inode));
|
|
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_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;
|
|
}
|
|
|
|
tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
|
|
error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
|
|
if (error) {
|
|
xfs_trans_cancel(tp, 0);
|
|
goto out_unlock;
|
|
}
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
|
|
ip->i_d.di_mode &= ~S_ISUID;
|
|
if (ip->i_d.di_mode & S_IXGRP)
|
|
ip->i_d.di_mode &= ~S_ISGID;
|
|
|
|
if (!(mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_COLLAPSE_RANGE)))
|
|
ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
|
|
|
|
xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
|
|
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
|
|
|
|
if (file->f_flags & O_DSYNC)
|
|
xfs_trans_set_sync(tp);
|
|
error = xfs_trans_commit(tp, 0);
|
|
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);
|
|
}
|
|
|
|
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_data_map_shared(ip);
|
|
if (ip->i_d.di_nextents > 0)
|
|
xfs_dir3_data_readahead(NULL, 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);
|
|
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, ctx, bufsize);
|
|
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;
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* This type is designed to indicate the type of offset we would like
|
|
* to search from page cache for either xfs_seek_data() or xfs_seek_hole().
|
|
*/
|
|
enum {
|
|
HOLE_OFF = 0,
|
|
DATA_OFF,
|
|
};
|
|
|
|
/*
|
|
* Lookup the desired type of offset from the given page.
|
|
*
|
|
* On success, return true and the offset argument will point to the
|
|
* start of the region that was found. Otherwise this function will
|
|
* return false and keep the offset argument unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_lookup_buffer_offset(
|
|
struct page *page,
|
|
loff_t *offset,
|
|
unsigned int type)
|
|
{
|
|
loff_t lastoff = page_offset(page);
|
|
bool found = false;
|
|
struct buffer_head *bh, *head;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
/*
|
|
* Unwritten extents that have data in the page
|
|
* cache covering them can be identified by the
|
|
* BH_Unwritten state flag. Pages with multiple
|
|
* buffers might have a mix of holes, data and
|
|
* unwritten extents - any buffer with valid
|
|
* data in it should have BH_Uptodate flag set
|
|
* on it.
|
|
*/
|
|
if (buffer_unwritten(bh) ||
|
|
buffer_uptodate(bh)) {
|
|
if (type == DATA_OFF)
|
|
found = true;
|
|
} else {
|
|
if (type == HOLE_OFF)
|
|
found = true;
|
|
}
|
|
|
|
if (found) {
|
|
*offset = lastoff;
|
|
break;
|
|
}
|
|
lastoff += bh->b_size;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* This routine is called to find out and return a data or hole offset
|
|
* from the page cache for unwritten extents according to the desired
|
|
* type for xfs_seek_data() or xfs_seek_hole().
|
|
*
|
|
* The argument offset is used to tell where we start to search from the
|
|
* page cache. Map is used to figure out the end points of the range to
|
|
* lookup pages.
|
|
*
|
|
* Return true if the desired type of offset was found, and the argument
|
|
* offset is filled with that address. Otherwise, return false and keep
|
|
* offset unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_find_get_desired_pgoff(
|
|
struct inode *inode,
|
|
struct xfs_bmbt_irec *map,
|
|
unsigned int type,
|
|
loff_t *offset)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct pagevec pvec;
|
|
pgoff_t index;
|
|
pgoff_t end;
|
|
loff_t endoff;
|
|
loff_t startoff = *offset;
|
|
loff_t lastoff = startoff;
|
|
bool found = false;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
index = startoff >> PAGE_CACHE_SHIFT;
|
|
endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
|
|
end = endoff >> PAGE_CACHE_SHIFT;
|
|
do {
|
|
int want;
|
|
unsigned nr_pages;
|
|
unsigned int i;
|
|
|
|
want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
|
|
nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
|
|
want);
|
|
/*
|
|
* No page mapped into given range. If we are searching holes
|
|
* and if this is the first time we got into the loop, it means
|
|
* that the given offset is landed in a hole, return it.
|
|
*
|
|
* If we have already stepped through some block buffers to find
|
|
* holes but they all contains data. In this case, the last
|
|
* offset is already updated and pointed to the end of the last
|
|
* mapped page, if it does not reach the endpoint to search,
|
|
* that means there should be a hole between them.
|
|
*/
|
|
if (nr_pages == 0) {
|
|
/* Data search found nothing */
|
|
if (type == DATA_OFF)
|
|
break;
|
|
|
|
ASSERT(type == HOLE_OFF);
|
|
if (lastoff == startoff || lastoff < endoff) {
|
|
found = true;
|
|
*offset = lastoff;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At lease we found one page. If this is the first time we
|
|
* step into the loop, and if the first page index offset is
|
|
* greater than the given search offset, a hole was found.
|
|
*/
|
|
if (type == HOLE_OFF && lastoff == startoff &&
|
|
lastoff < page_offset(pvec.pages[0])) {
|
|
found = true;
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
loff_t b_offset;
|
|
|
|
/*
|
|
* At this point, the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL),
|
|
* or even swizzled back from swapper_space to tmpfs
|
|
* file mapping. However, page->index will not change
|
|
* because we have a reference on the page.
|
|
*
|
|
* Searching done if the page index is out of range.
|
|
* If the current offset is not reaches the end of
|
|
* the specified search range, there should be a hole
|
|
* between them.
|
|
*/
|
|
if (page->index > end) {
|
|
if (type == HOLE_OFF && lastoff < endoff) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
lock_page(page);
|
|
/*
|
|
* Page truncated or invalidated(page->mapping == NULL).
|
|
* We can freely skip it and proceed to check the next
|
|
* page.
|
|
*/
|
|
if (unlikely(page->mapping != inode->i_mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!page_has_buffers(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
found = xfs_lookup_buffer_offset(page, &b_offset, type);
|
|
if (found) {
|
|
/*
|
|
* The found offset may be less than the start
|
|
* point to search if this is the first time to
|
|
* come here.
|
|
*/
|
|
*offset = max_t(loff_t, startoff, b_offset);
|
|
unlock_page(page);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We either searching data but nothing was found, or
|
|
* searching hole but found a data buffer. In either
|
|
* case, probably the next page contains the desired
|
|
* things, update the last offset to it so.
|
|
*/
|
|
lastoff = page_offset(page) + PAGE_SIZE;
|
|
unlock_page(page);
|
|
}
|
|
|
|
/*
|
|
* The number of returned pages less than our desired, search
|
|
* done. In this case, nothing was found for searching data,
|
|
* but we found a hole behind the last offset.
|
|
*/
|
|
if (nr_pages < want) {
|
|
if (type == HOLE_OFF) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
index = pvec.pages[i - 1]->index + 1;
|
|
pagevec_release(&pvec);
|
|
} while (index <= end);
|
|
|
|
out:
|
|
pagevec_release(&pvec);
|
|
return found;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_seek_data(
|
|
struct file *file,
|
|
loff_t start)
|
|
{
|
|
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;
|
|
|
|
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 a data extent */
|
|
if (map[i].br_startblock == DELAYSTARTBLOCK ||
|
|
(map[i].br_state == XFS_EXT_NORM &&
|
|
!isnullstartblock(map[i].br_startblock)))
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search data
|
|
* from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
DATA_OFF, &offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* map[0] is hole or its an unwritten extent but
|
|
* without data in page cache. Probably means that
|
|
* we are reading after EOF if nothing in map[1].
|
|
*/
|
|
if (nmap == 1) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Nothing was found, proceed to the next round of search
|
|
* if reading offset not beyond or hit EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
out:
|
|
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_seek_hole(
|
|
struct file *file,
|
|
loff_t start)
|
|
{
|
|
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 -XFS_ERROR(EIO);
|
|
|
|
lock = xfs_ilock_data_map_shared(ip);
|
|
|
|
isize = i_size_read(inode);
|
|
if (start >= isize) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
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 a hole */
|
|
if (map[i].br_startblock == HOLESTARTBLOCK)
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search hole
|
|
* from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
HOLE_OFF, &offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* map[0] contains data or its unwritten but contains
|
|
* data in page cache, probably means that we are
|
|
* reading after EOF. We should fix offset to point
|
|
* to the end of the file(i.e., there is an implicit
|
|
* hole at the end of any file).
|
|
*/
|
|
if (nmap == 1) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Both mappings contains data, proceed to the next round of
|
|
* search if the current reading offset not beyond or hit EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/*
|
|
* At this point, we must have found a hole. However, the returned
|
|
* offset may be bigger than the file size as it may be aligned to
|
|
* page boundary for unwritten extents, we need to deal with this
|
|
* situation in particular.
|
|
*/
|
|
offset = min_t(loff_t, offset, isize);
|
|
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 origin)
|
|
{
|
|
switch (origin) {
|
|
case SEEK_END:
|
|
case SEEK_CUR:
|
|
case SEEK_SET:
|
|
return generic_file_llseek(file, offset, origin);
|
|
case SEEK_DATA:
|
|
return xfs_seek_data(file, offset);
|
|
case SEEK_HOLE:
|
|
return xfs_seek_hole(file, offset);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
const struct file_operations xfs_file_operations = {
|
|
.llseek = xfs_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,
|
|
.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,
|
|
};
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops = {
|
|
.fault = filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.page_mkwrite = xfs_vm_page_mkwrite,
|
|
.remap_pages = generic_file_remap_pages,
|
|
};
|