v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
new file mode 100644
index 0000000..f2284ce
--- /dev/null
+++ b/fs/xfs/xfs_export.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2004-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.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_dir2.h"
+#include "xfs_export.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_inode_item.h"
+#include "xfs_trace.h"
+#include "xfs_icache.h"
+#include "xfs_log.h"
+#include "xfs_pnfs.h"
+
+/*
+ * Note that we only accept fileids which are long enough rather than allow
+ * the parent generation number to default to zero. XFS considers zero a
+ * valid generation number not an invalid/wildcard value.
+ */
+static int xfs_fileid_length(int fileid_type)
+{
+ switch (fileid_type) {
+ case FILEID_INO32_GEN:
+ return 2;
+ case FILEID_INO32_GEN_PARENT:
+ return 4;
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ return 3;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ return 6;
+ }
+ return FILEID_INVALID;
+}
+
+STATIC int
+xfs_fs_encode_fh(
+ struct inode *inode,
+ __u32 *fh,
+ int *max_len,
+ struct inode *parent)
+{
+ struct fid *fid = (struct fid *)fh;
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fh;
+ int fileid_type;
+ int len;
+
+ /* Directories don't need their parent encoded, they have ".." */
+ if (!parent)
+ fileid_type = FILEID_INO32_GEN;
+ else
+ fileid_type = FILEID_INO32_GEN_PARENT;
+
+ /*
+ * If the the filesystem may contain 64bit inode numbers, we need
+ * to use larger file handles that can represent them.
+ *
+ * While we only allocate inodes that do not fit into 32 bits any
+ * large enough filesystem may contain them, thus the slightly
+ * confusing looking conditional below.
+ */
+ if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
+ (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
+ fileid_type |= XFS_FILEID_TYPE_64FLAG;
+
+ /*
+ * Only encode if there is enough space given. In practice
+ * this means we can't export a filesystem with 64bit inodes
+ * over NFSv2 with the subtree_check export option; the other
+ * seven combinations work. The real answer is "don't use v2".
+ */
+ len = xfs_fileid_length(fileid_type);
+ if (*max_len < len) {
+ *max_len = len;
+ return FILEID_INVALID;
+ }
+ *max_len = len;
+
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ fid->i32.parent_ino = XFS_I(parent)->i_ino;
+ fid->i32.parent_gen = parent->i_generation;
+ /*FALLTHRU*/
+ case FILEID_INO32_GEN:
+ fid->i32.ino = XFS_I(inode)->i_ino;
+ fid->i32.gen = inode->i_generation;
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ fid64->parent_ino = XFS_I(parent)->i_ino;
+ fid64->parent_gen = parent->i_generation;
+ /*FALLTHRU*/
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ fid64->ino = XFS_I(inode)->i_ino;
+ fid64->gen = inode->i_generation;
+ break;
+ }
+
+ return fileid_type;
+}
+
+STATIC struct inode *
+xfs_nfs_get_inode(
+ struct super_block *sb,
+ u64 ino,
+ u32 generation)
+{
+ xfs_mount_t *mp = XFS_M(sb);
+ xfs_inode_t *ip;
+ int error;
+
+ /*
+ * NFS can sometimes send requests for ino 0. Fail them gracefully.
+ */
+ if (ino == 0)
+ return ERR_PTR(-ESTALE);
+
+ /*
+ * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
+ * fine and not an indication of a corrupted filesystem as clients can
+ * send invalid file handles and we have to handle it gracefully..
+ */
+ error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
+ if (error) {
+
+ /*
+ * EINVAL means the inode cluster doesn't exist anymore.
+ * EFSCORRUPTED means the metadata pointing to the inode cluster
+ * or the inode cluster itself is corrupt. This implies the
+ * filehandle is stale, so we should translate it here.
+ * We don't use ESTALE directly down the chain to not
+ * confuse applications using bulkstat that expect EINVAL.
+ */
+ switch (error) {
+ case -EINVAL:
+ case -ENOENT:
+ case -EFSCORRUPTED:
+ error = -ESTALE;
+ break;
+ default:
+ break;
+ }
+ return ERR_PTR(error);
+ }
+
+ if (VFS_I(ip)->i_generation != generation) {
+ xfs_irele(ip);
+ return ERR_PTR(-ESTALE);
+ }
+
+ return VFS_I(ip);
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fileid_type)
+{
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
+ struct inode *inode = NULL;
+
+ if (fh_len < xfs_fileid_length(fileid_type))
+ return NULL;
+
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ case FILEID_INO32_GEN:
+ inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
+ inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
+ break;
+ }
+
+ return d_obtain_alias(inode);
+}
+
+STATIC struct dentry *
+xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fileid_type)
+{
+ struct xfs_fid64 *fid64 = (struct xfs_fid64 *)fid;
+ struct inode *inode = NULL;
+
+ if (fh_len < xfs_fileid_length(fileid_type))
+ return NULL;
+
+ switch (fileid_type) {
+ case FILEID_INO32_GEN_PARENT:
+ inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
+ fid->i32.parent_gen);
+ break;
+ case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
+ inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
+ fid64->parent_gen);
+ break;
+ }
+
+ return d_obtain_alias(inode);
+}
+
+STATIC struct dentry *
+xfs_fs_get_parent(
+ struct dentry *child)
+{
+ int error;
+ struct xfs_inode *cip;
+
+ error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
+ if (unlikely(error))
+ return ERR_PTR(error);
+
+ return d_obtain_alias(VFS_I(cip));
+}
+
+STATIC int
+xfs_fs_nfs_commit_metadata(
+ struct inode *inode)
+{
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_lsn_t lsn = 0;
+
+ 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);
+}
+
+const struct export_operations xfs_export_operations = {
+ .encode_fh = xfs_fs_encode_fh,
+ .fh_to_dentry = xfs_fs_fh_to_dentry,
+ .fh_to_parent = xfs_fs_fh_to_parent,
+ .get_parent = xfs_fs_get_parent,
+ .commit_metadata = xfs_fs_nfs_commit_metadata,
+#ifdef CONFIG_EXPORTFS_BLOCK_OPS
+ .get_uuid = xfs_fs_get_uuid,
+ .map_blocks = xfs_fs_map_blocks,
+ .commit_blocks = xfs_fs_commit_blocks,
+#endif
+};