v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
new file mode 100644
index 0000000..61a5ad2
--- /dev/null
+++ b/fs/xfs/xfs_file.c
@@ -0,0 +1,1192 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_inode_item.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_error.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ioctl.h"
+#include "xfs_trace.h"
+#include "xfs_log.h"
+#include "xfs_icache.h"
+#include "xfs_pnfs.h"
+#include "xfs_iomap.h"
+#include "xfs_reflink.h"
+
+#include <linux/dcache.h>
+#include <linux/falloc.h>
+#include <linux/pagevec.h>
+#include <linux/backing-dev.h>
+#include <linux/mman.h>
+
+static const struct vm_operations_struct xfs_file_vm_ops;
+
+int
+xfs_update_prealloc_flags(
+ struct xfs_inode *ip,
+ enum xfs_prealloc_flags flags)
+{
+ struct xfs_trans *tp;
+ int error;
+
+ error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
+ 0, 0, 0, &tp);
+ if (error)
+ return error;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+ if (!(flags & XFS_PREALLOC_INVISIBLE)) {
+ VFS_I(ip)->i_mode &= ~S_ISUID;
+ if (VFS_I(ip)->i_mode & S_IXGRP)
+ VFS_I(ip)->i_mode &= ~S_ISGID;
+ xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ }
+
+ if (flags & XFS_PREALLOC_SET)
+ ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
+ if (flags & XFS_PREALLOC_CLEAR)
+ ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
+
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ if (flags & XFS_PREALLOC_SYNC)
+ xfs_trans_set_sync(tp);
+ return xfs_trans_commit(tp);
+}
+
+/*
+ * Fsync operations on directories are much simpler than on regular files,
+ * as there is no file data to flush, and thus also no need for explicit
+ * cache flush operations, and there are no non-transaction metadata updates
+ * on directories either.
+ */
+STATIC int
+xfs_dir_fsync(
+ struct file *file,
+ loff_t start,
+ loff_t end,
+ int datasync)
+{
+ struct xfs_inode *ip = XFS_I(file->f_mapping->host);
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_lsn_t lsn = 0;
+
+ trace_xfs_dir_fsync(ip);
+
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ if (xfs_ipincount(ip))
+ lsn = ip->i_itemp->ili_last_lsn;
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ if (!lsn)
+ return 0;
+ return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
+}
+
+STATIC int
+xfs_file_fsync(
+ struct file *file,
+ loff_t start,
+ loff_t end,
+ int datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ int error = 0;
+ int log_flushed = 0;
+ xfs_lsn_t lsn = 0;
+
+ trace_xfs_file_fsync(ip);
+
+ error = file_write_and_wait_range(file, start, end);
+ if (error)
+ return error;
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
+
+ xfs_iflags_clear(ip, XFS_ITRUNCATED);
+
+ /*
+ * If we have an RT and/or log subvolume we need to make sure to flush
+ * the write cache the device used for file data first. This is to
+ * ensure newly written file data make it to disk before logging the new
+ * inode size in case of an extending write.
+ */
+ if (XFS_IS_REALTIME_INODE(ip))
+ xfs_blkdev_issue_flush(mp->m_rtdev_targp);
+ else if (mp->m_logdev_targp != mp->m_ddev_targp)
+ xfs_blkdev_issue_flush(mp->m_ddev_targp);
+
+ /*
+ * All metadata updates are logged, which means that we just have to
+ * flush the log up to the latest LSN that touched the inode. If we have
+ * concurrent fsync/fdatasync() calls, we need them to all block on the
+ * log force before we clear the ili_fsync_fields field. This ensures
+ * that we don't get a racing sync operation that does not wait for the
+ * metadata to hit the journal before returning. If we race with
+ * clearing the ili_fsync_fields, then all that will happen is the log
+ * force will do nothing as the lsn will already be on disk. We can't
+ * race with setting ili_fsync_fields because that is done under
+ * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared
+ * until after the ili_fsync_fields is cleared.
+ */
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+ if (xfs_ipincount(ip)) {
+ if (!datasync ||
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ lsn = ip->i_itemp->ili_last_lsn;
+ }
+
+ if (lsn) {
+ error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
+ ip->i_itemp->ili_fsync_fields = 0;
+ }
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+ /*
+ * If we only have a single device, and the log force about was
+ * a no-op we might have to flush the data device cache here.
+ * This can only happen for fdatasync/O_DSYNC if we were overwriting
+ * an already allocated file and thus do not have any metadata to
+ * commit.
+ */
+ if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
+ mp->m_logdev_targp == mp->m_ddev_targp)
+ xfs_blkdev_issue_flush(mp->m_ddev_targp);
+
+ return error;
+}
+
+STATIC ssize_t
+xfs_file_dio_aio_read(
+ struct kiocb *iocb,
+ struct iov_iter *to)
+{
+ struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
+ size_t count = iov_iter_count(to);
+ ssize_t ret;
+
+ trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
+
+ if (!count)
+ return 0; /* skip atime */
+
+ file_accessed(iocb->ki_filp);
+
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ return ret;
+}
+
+static noinline ssize_t
+xfs_file_dax_read(
+ struct kiocb *iocb,
+ struct iov_iter *to)
+{
+ struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
+ size_t count = iov_iter_count(to);
+ ssize_t ret = 0;
+
+ trace_xfs_file_dax_read(ip, count, iocb->ki_pos);
+
+ if (!count)
+ return 0; /* skip atime */
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ }
+
+ ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ file_accessed(iocb->ki_filp);
+ return ret;
+}
+
+STATIC ssize_t
+xfs_file_buffered_aio_read(
+ struct kiocb *iocb,
+ struct iov_iter *to)
+{
+ struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
+ ssize_t ret;
+
+ trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+ }
+ ret = generic_file_read_iter(iocb, to);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ return ret;
+}
+
+STATIC ssize_t
+xfs_file_read_iter(
+ struct kiocb *iocb,
+ struct iov_iter *to)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct xfs_mount *mp = XFS_I(inode)->i_mount;
+ ssize_t ret = 0;
+
+ XFS_STATS_INC(mp, xs_read_calls);
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
+
+ if (IS_DAX(inode))
+ ret = xfs_file_dax_read(iocb, to);
+ else if (iocb->ki_flags & IOCB_DIRECT)
+ ret = xfs_file_dio_aio_read(iocb, to);
+ else
+ ret = xfs_file_buffered_aio_read(iocb, to);
+
+ if (ret > 0)
+ XFS_STATS_ADD(mp, xs_read_bytes, ret);
+ return ret;
+}
+
+/*
+ * Common pre-write limit and setup checks.
+ *
+ * Called with the iolocked held either shared and exclusive according to
+ * @iolock, and returns with it held. Might upgrade the iolock to exclusive
+ * if called for a direct write beyond i_size.
+ */
+STATIC ssize_t
+xfs_file_aio_write_checks(
+ struct kiocb *iocb,
+ struct iov_iter *from,
+ int *iolock)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ ssize_t error = 0;
+ size_t count = iov_iter_count(from);
+ bool drained_dio = false;
+ loff_t isize;
+
+restart:
+ error = generic_write_checks(iocb, from);
+ if (error <= 0)
+ return error;
+
+ error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
+ if (error)
+ return error;
+
+ /*
+ * For changing security info in file_remove_privs() we need i_rwsem
+ * exclusively.
+ */
+ if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
+ xfs_iunlock(ip, *iolock);
+ *iolock = XFS_IOLOCK_EXCL;
+ xfs_ilock(ip, *iolock);
+ goto restart;
+ }
+ /*
+ * If the offset is beyond the size of the file, we need to zero any
+ * blocks that fall between the existing EOF and the start of this
+ * write. If zeroing is needed and we are currently holding the
+ * iolock shared, we need to update it to exclusive which implies
+ * having to redo all checks before.
+ *
+ * We need to serialise against EOF updates that occur in IO
+ * completions here. We want to make sure that nobody is changing the
+ * size while we do this check until we have placed an IO barrier (i.e.
+ * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
+ * The spinlock effectively forms a memory barrier once we have the
+ * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
+ * and hence be able to correctly determine if we need to run zeroing.
+ */
+ spin_lock(&ip->i_flags_lock);
+ isize = i_size_read(inode);
+ if (iocb->ki_pos > isize) {
+ spin_unlock(&ip->i_flags_lock);
+ if (!drained_dio) {
+ if (*iolock == XFS_IOLOCK_SHARED) {
+ xfs_iunlock(ip, *iolock);
+ *iolock = XFS_IOLOCK_EXCL;
+ xfs_ilock(ip, *iolock);
+ iov_iter_reexpand(from, count);
+ }
+ /*
+ * We now have an IO submission barrier in place, but
+ * AIO can do EOF updates during IO completion and hence
+ * we now need to wait for all of them to drain. Non-AIO
+ * DIO will have drained before we are given the
+ * XFS_IOLOCK_EXCL, and so for most cases this wait is a
+ * no-op.
+ */
+ inode_dio_wait(inode);
+ drained_dio = true;
+ goto restart;
+ }
+
+ trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
+ error = iomap_zero_range(inode, isize, iocb->ki_pos - isize,
+ NULL, &xfs_iomap_ops);
+ if (error)
+ return error;
+ } else
+ spin_unlock(&ip->i_flags_lock);
+
+ /*
+ * Updating the timestamps will grab the ilock again from
+ * xfs_fs_dirty_inode, so we have to call it after dropping the
+ * lock above. Eventually we should look into a way to avoid
+ * the pointless lock roundtrip.
+ */
+ if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
+ error = file_update_time(file);
+ if (error)
+ return error;
+ }
+
+ /*
+ * If we're writing the file then make sure to clear the setuid and
+ * setgid bits if the process is not being run by root. This keeps
+ * people from modifying setuid and setgid binaries.
+ */
+ if (!IS_NOSEC(inode))
+ return file_remove_privs(file);
+ return 0;
+}
+
+static int
+xfs_dio_write_end_io(
+ struct kiocb *iocb,
+ ssize_t size,
+ unsigned flags)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct xfs_inode *ip = XFS_I(inode);
+ loff_t offset = iocb->ki_pos;
+ int error = 0;
+
+ trace_xfs_end_io_direct_write(ip, offset, size);
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ if (size <= 0)
+ return size;
+
+ /*
+ * Capture amount written on completion as we can't reliably account
+ * for it on submission.
+ */
+ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
+
+ if (flags & IOMAP_DIO_COW) {
+ error = xfs_reflink_end_cow(ip, offset, size);
+ if (error)
+ return error;
+ }
+
+ /*
+ * Unwritten conversion updates the in-core isize after extent
+ * conversion but before updating the on-disk size. Updating isize any
+ * earlier allows a racing dio read to find unwritten extents before
+ * they are converted.
+ */
+ if (flags & IOMAP_DIO_UNWRITTEN)
+ return xfs_iomap_write_unwritten(ip, offset, size, true);
+
+ /*
+ * We need to update the in-core inode size here so that we don't end up
+ * with the on-disk inode size being outside the in-core inode size. We
+ * have no other method of updating EOF for AIO, so always do it here
+ * if necessary.
+ *
+ * We need to lock the test/set EOF update as we can be racing with
+ * other IO completions here to update the EOF. Failing to serialise
+ * here can result in EOF moving backwards and Bad Things Happen when
+ * that occurs.
+ */
+ spin_lock(&ip->i_flags_lock);
+ if (offset + size > i_size_read(inode)) {
+ i_size_write(inode, offset + size);
+ spin_unlock(&ip->i_flags_lock);
+ error = xfs_setfilesize(ip, offset, size);
+ } else {
+ spin_unlock(&ip->i_flags_lock);
+ }
+
+ return error;
+}
+
+/*
+ * xfs_file_dio_aio_write - handle direct IO writes
+ *
+ * Lock the inode appropriately to prepare for and issue a direct IO write.
+ * By separating it from the buffered write path we remove all the tricky to
+ * follow locking changes and looping.
+ *
+ * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
+ * until we're sure the bytes at the new EOF have been zeroed and/or the cached
+ * pages are flushed out.
+ *
+ * In most cases the direct IO writes will be done holding IOLOCK_SHARED
+ * allowing them to be done in parallel with reads and other direct IO writes.
+ * However, if the IO is not aligned to filesystem blocks, the direct IO layer
+ * needs to do sub-block zeroing and that requires serialisation against other
+ * direct IOs to the same block. In this case we need to serialise the
+ * submission of the unaligned IOs so that we don't get racing block zeroing in
+ * the dio layer. To avoid the problem with aio, we also need to wait for
+ * outstanding IOs to complete so that unwritten extent conversion is completed
+ * before we try to map the overlapping block. This is currently implemented by
+ * hitting it with a big hammer (i.e. inode_dio_wait()).
+ *
+ * Returns with locks held indicated by @iolock and errors indicated by
+ * negative return values.
+ */
+STATIC ssize_t
+xfs_file_dio_aio_write(
+ struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ ssize_t ret = 0;
+ int unaligned_io = 0;
+ int iolock;
+ size_t count = iov_iter_count(from);
+ struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
+ mp->m_rtdev_targp : mp->m_ddev_targp;
+
+ /* DIO must be aligned to device logical sector size */
+ if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
+ return -EINVAL;
+
+ /*
+ * Don't take the exclusive iolock here unless the I/O is unaligned to
+ * the file system block size. We don't need to consider the EOF
+ * extension case here because xfs_file_aio_write_checks() will relock
+ * the inode as necessary for EOF zeroing cases and fill out the new
+ * inode size as appropriate.
+ */
+ if ((iocb->ki_pos & mp->m_blockmask) ||
+ ((iocb->ki_pos + count) & mp->m_blockmask)) {
+ unaligned_io = 1;
+
+ /*
+ * We can't properly handle unaligned direct I/O to reflink
+ * files yet, as we can't unshare a partial block.
+ */
+ if (xfs_is_reflink_inode(ip)) {
+ trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count);
+ return -EREMCHG;
+ }
+ iolock = XFS_IOLOCK_EXCL;
+ } else {
+ iolock = XFS_IOLOCK_SHARED;
+ }
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!xfs_ilock_nowait(ip, iolock))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, iolock);
+ }
+
+ ret = xfs_file_aio_write_checks(iocb, from, &iolock);
+ if (ret)
+ goto out;
+ count = iov_iter_count(from);
+
+ /*
+ * If we are doing unaligned IO, wait for all other IO to drain,
+ * otherwise demote the lock if we had to take the exclusive lock
+ * for other reasons in xfs_file_aio_write_checks.
+ */
+ if (unaligned_io) {
+ /* If we are going to wait for other DIO to finish, bail */
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (atomic_read(&inode->i_dio_count))
+ return -EAGAIN;
+ } else {
+ inode_dio_wait(inode);
+ }
+ } else if (iolock == XFS_IOLOCK_EXCL) {
+ xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
+ iolock = XFS_IOLOCK_SHARED;
+ }
+
+ trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
+ ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
+out:
+ xfs_iunlock(ip, iolock);
+
+ /*
+ * No fallback to buffered IO on errors for XFS, direct IO will either
+ * complete fully or fail.
+ */
+ ASSERT(ret < 0 || ret == count);
+ return ret;
+}
+
+static noinline ssize_t
+xfs_file_dax_write(
+ struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ int iolock = XFS_IOLOCK_EXCL;
+ ssize_t ret, error = 0;
+ size_t count;
+ loff_t pos;
+
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!xfs_ilock_nowait(ip, iolock))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, iolock);
+ }
+
+ ret = xfs_file_aio_write_checks(iocb, from, &iolock);
+ if (ret)
+ goto out;
+
+ pos = iocb->ki_pos;
+ count = iov_iter_count(from);
+
+ trace_xfs_file_dax_write(ip, count, pos);
+ ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
+ if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
+ i_size_write(inode, iocb->ki_pos);
+ error = xfs_setfilesize(ip, pos, ret);
+ }
+out:
+ xfs_iunlock(ip, iolock);
+ if (error)
+ return error;
+
+ if (ret > 0) {
+ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
+
+ /* Handle various SYNC-type writes */
+ ret = generic_write_sync(iocb, ret);
+ }
+ return ret;
+}
+
+STATIC ssize_t
+xfs_file_buffered_aio_write(
+ struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ ssize_t ret;
+ int enospc = 0;
+ int iolock;
+
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ return -EOPNOTSUPP;
+
+write_retry:
+ iolock = XFS_IOLOCK_EXCL;
+ xfs_ilock(ip, iolock);
+
+ ret = xfs_file_aio_write_checks(iocb, from, &iolock);
+ if (ret)
+ goto out;
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = inode_to_bdi(inode);
+
+ trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos);
+ ret = iomap_file_buffered_write(iocb, from, &xfs_iomap_ops);
+ if (likely(ret >= 0))
+ iocb->ki_pos += ret;
+
+ /*
+ * If we hit a space limit, try to free up some lingering preallocated
+ * space before returning an error. In the case of ENOSPC, first try to
+ * write back all dirty inodes to free up some of the excess reserved
+ * metadata space. This reduces the chances that the eofblocks scan
+ * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
+ * also behaves as a filter to prevent too many eofblocks scans from
+ * running at the same time.
+ */
+ if (ret == -EDQUOT && !enospc) {
+ xfs_iunlock(ip, iolock);
+ enospc = xfs_inode_free_quota_eofblocks(ip);
+ if (enospc)
+ goto write_retry;
+ enospc = xfs_inode_free_quota_cowblocks(ip);
+ if (enospc)
+ goto write_retry;
+ iolock = 0;
+ } else if (ret == -ENOSPC && !enospc) {
+ struct xfs_eofblocks eofb = {0};
+
+ enospc = 1;
+ xfs_flush_inodes(ip->i_mount);
+
+ xfs_iunlock(ip, iolock);
+ eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
+ xfs_icache_free_eofblocks(ip->i_mount, &eofb);
+ xfs_icache_free_cowblocks(ip->i_mount, &eofb);
+ goto write_retry;
+ }
+
+ current->backing_dev_info = NULL;
+out:
+ if (iolock)
+ xfs_iunlock(ip, iolock);
+
+ if (ret > 0) {
+ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
+ /* Handle various SYNC-type writes */
+ ret = generic_write_sync(iocb, ret);
+ }
+ return ret;
+}
+
+STATIC ssize_t
+xfs_file_write_iter(
+ struct kiocb *iocb,
+ struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ ssize_t ret;
+ size_t ocount = iov_iter_count(from);
+
+ XFS_STATS_INC(ip->i_mount, xs_write_calls);
+
+ if (ocount == 0)
+ return 0;
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ if (IS_DAX(inode))
+ return xfs_file_dax_write(iocb, from);
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ /*
+ * Allow a directio write to fall back to a buffered
+ * write *only* in the case that we're doing a reflink
+ * CoW. In all other directio scenarios we do not
+ * allow an operation to fall back to buffered mode.
+ */
+ ret = xfs_file_dio_aio_write(iocb, from);
+ if (ret != -EREMCHG)
+ return ret;
+ }
+
+ return xfs_file_buffered_aio_write(iocb, from);
+}
+
+static void
+xfs_wait_dax_page(
+ struct inode *inode)
+{
+ struct xfs_inode *ip = XFS_I(inode);
+
+ xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
+ schedule();
+ xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+}
+
+static int
+xfs_break_dax_layouts(
+ struct inode *inode,
+ bool *retry)
+{
+ struct page *page;
+
+ ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));
+
+ page = dax_layout_busy_page(inode->i_mapping);
+ if (!page)
+ return 0;
+
+ *retry = true;
+ return ___wait_var_event(&page->_refcount,
+ atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
+ 0, 0, xfs_wait_dax_page(inode));
+}
+
+int
+xfs_break_layouts(
+ struct inode *inode,
+ uint *iolock,
+ enum layout_break_reason reason)
+{
+ bool retry;
+ int error;
+
+ ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
+
+ do {
+ retry = false;
+ switch (reason) {
+ case BREAK_UNMAP:
+ error = xfs_break_dax_layouts(inode, &retry);
+ if (error || retry)
+ break;
+ /* fall through */
+ case BREAK_WRITE:
+ error = xfs_break_leased_layouts(inode, iolock, &retry);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ error = -EINVAL;
+ }
+ } while (error == 0 && retry);
+
+ return error;
+}
+
+#define XFS_FALLOC_FL_SUPPORTED \
+ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
+ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
+ FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
+
+STATIC long
+xfs_file_fallocate(
+ struct file *file,
+ int mode,
+ loff_t offset,
+ loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct xfs_inode *ip = XFS_I(inode);
+ long error;
+ enum xfs_prealloc_flags flags = 0;
+ uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+ loff_t new_size = 0;
+ bool do_file_insert = false;
+
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+ if (mode & ~XFS_FALLOC_FL_SUPPORTED)
+ return -EOPNOTSUPP;
+
+ xfs_ilock(ip, iolock);
+ error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
+ if (error)
+ goto out_unlock;
+
+ if (mode & FALLOC_FL_PUNCH_HOLE) {
+ error = xfs_free_file_space(ip, offset, len);
+ if (error)
+ goto out_unlock;
+ } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
+ unsigned int blksize_mask = i_blocksize(inode) - 1;
+
+ if (offset & blksize_mask || len & blksize_mask) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ /*
+ * There is no need to overlap collapse range with EOF,
+ * in which case it is effectively a truncate operation
+ */
+ if (offset + len >= i_size_read(inode)) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ new_size = i_size_read(inode) - len;
+
+ error = xfs_collapse_file_space(ip, offset, len);
+ if (error)
+ goto out_unlock;
+ } else if (mode & FALLOC_FL_INSERT_RANGE) {
+ unsigned int blksize_mask = i_blocksize(inode) - 1;
+ loff_t isize = i_size_read(inode);
+
+ if (offset & blksize_mask || len & blksize_mask) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ /*
+ * New inode size must not exceed ->s_maxbytes, accounting for
+ * possible signed overflow.
+ */
+ if (inode->i_sb->s_maxbytes - isize < len) {
+ error = -EFBIG;
+ goto out_unlock;
+ }
+ new_size = isize + len;
+
+ /* Offset should be less than i_size */
+ if (offset >= isize) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+ do_file_insert = true;
+ } else {
+ flags |= XFS_PREALLOC_SET;
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ offset + len > i_size_read(inode)) {
+ new_size = offset + len;
+ error = inode_newsize_ok(inode, new_size);
+ if (error)
+ goto out_unlock;
+ }
+
+ if (mode & FALLOC_FL_ZERO_RANGE)
+ error = xfs_zero_file_space(ip, offset, len);
+ else {
+ if (mode & FALLOC_FL_UNSHARE_RANGE) {
+ error = xfs_reflink_unshare(ip, offset, len);
+ if (error)
+ goto out_unlock;
+ }
+ error = xfs_alloc_file_space(ip, offset, len,
+ XFS_BMAPI_PREALLOC);
+ }
+ if (error)
+ goto out_unlock;
+ }
+
+ if (file->f_flags & O_DSYNC)
+ flags |= XFS_PREALLOC_SYNC;
+
+ error = xfs_update_prealloc_flags(ip, flags);
+ if (error)
+ goto out_unlock;
+
+ /* Change file size if needed */
+ if (new_size) {
+ struct iattr iattr;
+
+ iattr.ia_valid = ATTR_SIZE;
+ iattr.ia_size = new_size;
+ error = xfs_vn_setattr_size(file_dentry(file), &iattr);
+ if (error)
+ goto out_unlock;
+ }
+
+ /*
+ * Perform hole insertion now that the file size has been
+ * updated so that if we crash during the operation we don't
+ * leave shifted extents past EOF and hence losing access to
+ * the data that is contained within them.
+ */
+ if (do_file_insert)
+ error = xfs_insert_file_space(ip, offset, len);
+
+out_unlock:
+ xfs_iunlock(ip, iolock);
+ return error;
+}
+
+STATIC int
+xfs_file_clone_range(
+ struct file *file_in,
+ loff_t pos_in,
+ struct file *file_out,
+ loff_t pos_out,
+ u64 len)
+{
+ return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
+ len, false);
+}
+
+STATIC int
+xfs_file_dedupe_range(
+ struct file *file_in,
+ loff_t pos_in,
+ struct file *file_out,
+ loff_t pos_out,
+ u64 len)
+{
+ return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
+ len, true);
+}
+
+STATIC int
+xfs_file_open(
+ struct inode *inode,
+ struct file *file)
+{
+ if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
+ return -EFBIG;
+ if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
+ return -EIO;
+ file->f_mode |= FMODE_NOWAIT;
+ return 0;
+}
+
+STATIC int
+xfs_dir_open(
+ struct inode *inode,
+ struct file *file)
+{
+ struct xfs_inode *ip = XFS_I(inode);
+ int mode;
+ int error;
+
+ error = xfs_file_open(inode, file);
+ if (error)
+ return error;
+
+ /*
+ * If there are any blocks, read-ahead block 0 as we're almost
+ * certain to have the next operation be a read there.
+ */
+ mode = xfs_ilock_data_map_shared(ip);
+ if (ip->i_d.di_nextents > 0)
+ error = xfs_dir3_data_readahead(ip, 0, -1);
+ xfs_iunlock(ip, mode);
+ return error;
+}
+
+STATIC int
+xfs_file_release(
+ struct inode *inode,
+ struct file *filp)
+{
+ return xfs_release(XFS_I(inode));
+}
+
+STATIC int
+xfs_file_readdir(
+ struct file *file,
+ struct dir_context *ctx)
+{
+ struct inode *inode = file_inode(file);
+ xfs_inode_t *ip = XFS_I(inode);
+ size_t bufsize;
+
+ /*
+ * The Linux API doesn't pass down the total size of the buffer
+ * we read into down to the filesystem. With the filldir concept
+ * it's not needed for correct information, but the XFS dir2 leaf
+ * code wants an estimate of the buffer size to calculate it's
+ * readahead window and size the buffers used for mapping to
+ * physical blocks.
+ *
+ * Try to give it an estimate that's good enough, maybe at some
+ * point we can change the ->readdir prototype to include the
+ * buffer size. For now we use the current glibc buffer size.
+ */
+ bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_d.di_size);
+
+ return xfs_readdir(NULL, ip, ctx, bufsize);
+}
+
+STATIC loff_t
+xfs_file_llseek(
+ struct file *file,
+ loff_t offset,
+ int whence)
+{
+ struct inode *inode = file->f_mapping->host;
+
+ if (XFS_FORCED_SHUTDOWN(XFS_I(inode)->i_mount))
+ return -EIO;
+
+ switch (whence) {
+ default:
+ return generic_file_llseek(file, offset, whence);
+ case SEEK_HOLE:
+ offset = iomap_seek_hole(inode, offset, &xfs_iomap_ops);
+ break;
+ case SEEK_DATA:
+ offset = iomap_seek_data(inode, offset, &xfs_iomap_ops);
+ break;
+ }
+
+ if (offset < 0)
+ return offset;
+ return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
+}
+
+/*
+ * Locking for serialisation of IO during page faults. This results in a lock
+ * ordering of:
+ *
+ * mmap_sem (MM)
+ * sb_start_pagefault(vfs, freeze)
+ * i_mmaplock (XFS - truncate serialisation)
+ * page_lock (MM)
+ * i_lock (XFS - extent map serialisation)
+ */
+static vm_fault_t
+__xfs_filemap_fault(
+ struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ bool write_fault)
+{
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct xfs_inode *ip = XFS_I(inode);
+ vm_fault_t ret;
+
+ trace_xfs_filemap_fault(ip, pe_size, write_fault);
+
+ if (write_fault) {
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vmf->vma->vm_file);
+ }
+
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+ if (IS_DAX(inode)) {
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
+ } else {
+ if (write_fault)
+ ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
+ else
+ ret = filemap_fault(vmf);
+ }
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+
+ if (write_fault)
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static vm_fault_t
+xfs_filemap_fault(
+ struct vm_fault *vmf)
+{
+ /* DAX can shortcut the normal fault path on write faults! */
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
+ IS_DAX(file_inode(vmf->vma->vm_file)) &&
+ (vmf->flags & FAULT_FLAG_WRITE));
+}
+
+static vm_fault_t
+xfs_filemap_huge_fault(
+ struct vm_fault *vmf,
+ enum page_entry_size pe_size)
+{
+ if (!IS_DAX(file_inode(vmf->vma->vm_file)))
+ return VM_FAULT_FALLBACK;
+
+ /* DAX can shortcut the normal fault path on write faults! */
+ return __xfs_filemap_fault(vmf, pe_size,
+ (vmf->flags & FAULT_FLAG_WRITE));
+}
+
+static vm_fault_t
+xfs_filemap_page_mkwrite(
+ struct vm_fault *vmf)
+{
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
+}
+
+/*
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
+ */
+static vm_fault_t
+xfs_filemap_pfn_mkwrite(
+ struct vm_fault *vmf)
+{
+
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
+}
+
+static const struct vm_operations_struct xfs_file_vm_ops = {
+ .fault = xfs_filemap_fault,
+ .huge_fault = xfs_filemap_huge_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = xfs_filemap_page_mkwrite,
+ .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
+};
+
+STATIC int
+xfs_file_mmap(
+ struct file *filp,
+ struct vm_area_struct *vma)
+{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
+ file_accessed(filp);
+ vma->vm_ops = &xfs_file_vm_ops;
+ if (IS_DAX(file_inode(filp)))
+ vma->vm_flags |= VM_HUGEPAGE;
+ return 0;
+}
+
+const struct file_operations xfs_file_operations = {
+ .llseek = xfs_file_llseek,
+ .read_iter = xfs_file_read_iter,
+ .write_iter = xfs_file_write_iter,
+ .splice_read = generic_file_splice_read,
+ .splice_write = iter_file_splice_write,
+ .unlocked_ioctl = xfs_file_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = xfs_file_compat_ioctl,
+#endif
+ .mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
+ .open = xfs_file_open,
+ .release = xfs_file_release,
+ .fsync = xfs_file_fsync,
+ .get_unmapped_area = thp_get_unmapped_area,
+ .fallocate = xfs_file_fallocate,
+ .clone_file_range = xfs_file_clone_range,
+ .dedupe_file_range = xfs_file_dedupe_range,
+};
+
+const struct file_operations xfs_dir_file_operations = {
+ .open = xfs_dir_open,
+ .read = generic_read_dir,
+ .iterate_shared = xfs_file_readdir,
+ .llseek = generic_file_llseek,
+ .unlocked_ioctl = xfs_file_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = xfs_file_compat_ioctl,
+#endif
+ .fsync = xfs_dir_fsync,
+};