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LU-12400 llite: Use the new vm_fault_t type
[fs/lustre-release.git] / lustre / include / lustre_compat.h
index 0c0dc91..4175c82 100644 (file)
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2014, Intel Corporation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #ifndef _LUSTRE_COMPAT_H
 #define _LUSTRE_COMPAT_H
 
+#include <linux/aio.h>
+#include <linux/fs.h>
 #include <linux/fs_struct.h>
 #include <linux/namei.h>
-
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/xattr.h>
+#include <linux/workqueue.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+
+#include <libcfs/linux/linux-fs.h>
 #include <lustre_patchless_compat.h>
+#include <obd_support.h>
 
 #ifdef HAVE_FS_STRUCT_RWLOCK
 # define LOCK_FS_STRUCT(fs)    write_lock(&(fs)->lock)
 # define UNLOCK_FS_STRUCT(fs)  spin_unlock(&(fs)->lock)
 #endif
 
+#ifdef HAVE_FS_STRUCT_SEQCOUNT
+# define WRITE_FS_SEQ_BEGIN(fs)        write_seqcount_begin(&(fs)->seq)
+# define WRITE_FS_SEQ_END(fs)  write_seqcount_end(&(fs)->seq)
+#else
+# define WRITE_FS_SEQ_BEGIN(fs)
+# define WRITE_FS_SEQ_END(fs)
+#endif
 static inline void ll_set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
                                  struct dentry *dentry)
 {
-        struct path path;
-        struct path old_pwd;
-
-        path.mnt = mnt;
-        path.dentry = dentry;
-        LOCK_FS_STRUCT(fs);
-        old_pwd = fs->pwd;
-        path_get(&path);
-        fs->pwd = path;
-        UNLOCK_FS_STRUCT(fs);
-
-        if (old_pwd.dentry)
-                path_put(&old_pwd);
+       struct path path;
+       struct path old_pwd;
+
+       path.mnt = mnt;
+       path.dentry = dentry;
+       path_get(&path);
+       LOCK_FS_STRUCT(fs);
+       WRITE_FS_SEQ_BEGIN(fs);
+       old_pwd = fs->pwd;
+       fs->pwd = path;
+       WRITE_FS_SEQ_END(fs);
+       UNLOCK_FS_STRUCT(fs);
+
+       if (old_pwd.dentry)
+               path_put(&old_pwd);
 }
 
-/*
- * set ATTR_BLOCKS to a high value to avoid any risk of collision with other
- * ATTR_* attributes (see bug 13828)
- */
-#define ATTR_BLOCKS    (1 << 27)
-
 #define current_ngroups current_cred()->group_info->ngroups
 #define current_groups current_cred()->group_info->small_block
 
@@ -91,8 +100,6 @@ static inline void ll_set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
 #define MODULE_ALIAS_FS(name)
 #endif
 
-#define LTIME_S(time)                   (time.tv_sec)
-
 #ifdef HAVE_GENERIC_PERMISSION_2ARGS
 # define ll_generic_permission(inode, mask, flags, check_acl) \
         generic_permission(inode, mask)
@@ -123,50 +130,21 @@ static inline void ll_set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt,
 #ifdef HAVE_INODE_DIO_WAIT
 /* inode_dio_wait(i) use as-is for write lock */
 # define inode_dio_write_done(i)       do {} while (0) /* for write unlock */
-# define inode_dio_read(i)             atomic_inc(&(i)->i_dio_count)
-/* inode_dio_done(i) use as-is for read unlock */
 #else
 # define inode_dio_wait(i)             down_write(&(i)->i_alloc_sem)
 # define inode_dio_write_done(i)       up_write(&(i)->i_alloc_sem)
-# define inode_dio_read(i)             down_read(&(i)->i_alloc_sem)
-# define inode_dio_done(i)             up_read(&(i)->i_alloc_sem)
 #endif
 
-#ifndef FS_HAS_FIEMAP
-#define FS_HAS_FIEMAP                  (0)
-#endif
-
-/* add a lustre compatible layer for crypto API */
-#include <linux/crypto.h>
-static inline int ll_crypto_hmac(struct crypto_hash *tfm,
-                                 u8 *key, unsigned int *keylen,
-                                 struct scatterlist *sg,
-                                 unsigned int size, u8 *result)
-{
-        struct hash_desc desc;
-        int              rv;
-        desc.tfm   = tfm;
-        desc.flags = 0;
-        rv = crypto_hash_setkey(desc.tfm, key, *keylen);
-        if (rv) {
-                CERROR("failed to hash setkey: %d\n", rv);
-                return rv;
-        }
-        return crypto_hash_digest(&desc, sg, size, result);
-}
-
-static inline
-unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
-{
-        return crypto_blkcipher_tfm(tfm)->__crt_alg->cra_blkcipher.min_keysize;
-}
-
 #ifndef HAVE_SIMPLE_SETATTR
 #define simple_setattr(dentry, ops) inode_setattr((dentry)->d_inode, ops)
 #endif
 
-#ifndef SLAB_DESTROY_BY_RCU
-#define SLAB_DESTROY_BY_RCU 0
+#ifndef HAVE_INIT_LIST_HEAD_RCU
+static inline void INIT_LIST_HEAD_RCU(struct list_head *list)
+{
+       WRITE_ONCE(list->next, list);
+       WRITE_ONCE(list->prev, list);
+}
 #endif
 
 #ifndef HAVE_DQUOT_SUSPEND
@@ -188,6 +166,7 @@ unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
 #ifdef HAVE_BVEC_ITER
 #define bio_idx(bio)                   (bio->bi_iter.bi_idx)
 #define bio_set_sector(bio, sector)    (bio->bi_iter.bi_sector = sector)
+#define bvl_to_page(bvl)               (bvl->bv_page)
 #else
 #define bio_idx(bio)                   (bio->bi_idx)
 #define bio_set_sector(bio, sector)    (bio->bi_sector = sector)
@@ -195,7 +174,13 @@ unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
 #ifndef HAVE_BIO_END_SECTOR
 #define bio_end_sector(bio)            (bio->bi_sector + bio_sectors(bio))
 #endif
-#define bvec_iter_page(bvec, iter)     (*bvec->bv_page)
+#define bvl_to_page(bvl)               (bvl->bv_page)
+#endif
+
+#ifdef HAVE_BVEC_ITER
+#define bio_start_sector(bio) (bio->bi_iter.bi_sector)
+#else
+#define bio_start_sector(bio) (bio->bi_sector)
 #endif
 
 #ifndef HAVE_BLK_QUEUE_MAX_SEGMENTS
@@ -207,6 +192,14 @@ unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
 #define queue_max_hw_segments(rq)         queue_max_segments(rq)
 #endif
 
+#ifdef HAVE_BLK_PLUG
+#define DECLARE_PLUG(plug)     struct blk_plug plug
+#else /* !HAVE_BLK_PLUG */
+#define DECLARE_PLUG(name)
+#define blk_start_plug(plug)   do {} while (0)
+#define blk_finish_plug(plug)  do {} while (0)
+#endif
+
 #ifdef HAVE_KMAP_ATOMIC_HAS_1ARG
 #define ll_kmap_atomic(a, b)   kmap_atomic(a)
 #define ll_kunmap_atomic(a, b) kunmap_atomic(a)
@@ -250,6 +243,13 @@ unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
 #define DECLARE_LL_D_HLIST_NODE_PTR(name) /* nothing */
 #endif /* !DATA_FOR_LLITE_IS_LIST */
 
+#ifndef HAVE_D_IN_LOOKUP
+static inline int d_in_lookup(struct dentry *dentry)
+{
+       return false;
+}
+#endif
+
 #ifndef QUOTA_OK
 # define QUOTA_OK 0
 #endif
@@ -282,6 +282,14 @@ unsigned int ll_crypto_tfm_alg_min_keysize(struct crypto_blkcipher *tfm)
 # define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET)
 #endif
 
+#ifndef XATTR_NAME_POSIX_ACL_ACCESS
+# define XATTR_NAME_POSIX_ACL_ACCESS POSIX_ACL_XATTR_ACCESS
+#endif
+
+#ifndef XATTR_NAME_POSIX_ACL_DEFAULT
+# define XATTR_NAME_POSIX_ACL_DEFAULT POSIX_ACL_XATTR_DEFAULT
+#endif
+
 #ifndef HAVE_LM_XXX_LOCK_MANAGER_OPS
 # define lm_compare_owner      fl_compare_owner
 #endif
@@ -301,14 +309,6 @@ static inline int ll_namei_to_lookup_intent_flag(int flag)
        return flag;
 }
 
-#ifdef HAVE_VOID_MAKE_REQUEST_FN
-# define ll_mrf_ret void
-# define LL_MRF_RETURN(rc)
-#else
-# define ll_mrf_ret int
-# define LL_MRF_RETURN(rc) RETURN(rc)
-#endif
-
 #include <linux/fs.h>
 #ifndef HAVE_PROTECT_I_NLINK
 static inline void set_nlink(struct inode *inode, unsigned int nlink)
@@ -323,6 +323,10 @@ static inline void set_nlink(struct inode *inode, unsigned int nlink)
 # define ll_umode_t    int
 #endif
 
+#ifndef HAVE_VM_FAULT_T
+#define vm_fault_t int
+#endif
+
 #include <linux/dcache.h>
 #ifndef HAVE_D_MAKE_ROOT
 static inline struct dentry *d_make_root(struct inode *root)
@@ -348,6 +352,13 @@ static inline struct dentry *d_make_root(struct inode *root)
 # define set_file_inode(file, inode)
 #endif
 
+#ifndef HAVE_FILE_INODE
+static inline struct inode *file_inode(const struct file *file)
+{
+       return file->f_path.dentry->d_inode;
+}
+#endif
+
 #ifdef HAVE_OLDSIZE_TRUNCATE_PAGECACHE
 #define ll_truncate_pagecache(inode, size) truncate_pagecache(inode, 0, size)
 #else
@@ -368,6 +379,43 @@ static inline struct dentry *d_make_root(struct inode *root)
 #define ll_vfs_unlink(a, b) vfs_unlink(a, b)
 #endif
 
+#ifndef HAVE_INODE_OWNER_OR_CAPABLE
+#define inode_owner_or_capable(inode) is_owner_or_cap(inode)
+#endif
+
+static inline int ll_vfs_getattr(struct path *path, struct kstat *st)
+{
+       int rc;
+
+#ifdef HAVE_INODEOPS_ENHANCED_GETATTR
+       rc = vfs_getattr(path, st, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+#elif defined HAVE_VFS_GETATTR_2ARGS
+       rc = vfs_getattr(path, st);
+#else
+       rc = vfs_getattr(path->mnt, path->dentry, st);
+#endif
+       return rc;
+}
+
+#ifndef HAVE_D_IS_POSITIVE
+static inline bool d_is_positive(const struct dentry *dentry)
+{
+       return dentry->d_inode != NULL;
+}
+#endif
+
+#ifdef HAVE_VFS_CREATE_USE_NAMEIDATA
+# define LL_VFS_CREATE_FALSE NULL
+#else
+# define LL_VFS_CREATE_FALSE false
+#endif
+
+#ifndef HAVE_INODE_LOCK
+# define inode_lock(inode) mutex_lock(&(inode)->i_mutex)
+# define inode_unlock(inode) mutex_unlock(&(inode)->i_mutex)
+# define inode_trylock(inode) mutex_trylock(&(inode)->i_mutex)
+#endif
+
 #ifndef HAVE_RADIX_EXCEPTION_ENTRY
 static inline int radix_tree_exceptional_entry(void *arg)
 {
@@ -379,11 +427,16 @@ static inline int radix_tree_exceptional_entry(void *arg)
 static inline void truncate_inode_pages_final(struct address_space *map)
 {
        truncate_inode_pages(map, 0);
-               /* Workaround for LU-118 */
-       if (map->nrpages) {
-               spin_lock_irq(&map->tree_lock);
-               spin_unlock_irq(&map->tree_lock);
-       }       /* Workaround end */
+}
+#endif
+
+#ifndef HAVE_PTR_ERR_OR_ZERO
+static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr)
+{
+       if (IS_ERR(ptr))
+               return PTR_ERR(ptr);
+       else
+               return 0;
 }
 #endif
 
@@ -391,4 +444,410 @@ static inline void truncate_inode_pages_final(struct address_space *map)
 #define SIZE_MAX       (~(size_t)0)
 #endif
 
+#ifdef HAVE_SECURITY_IINITSEC_CALLBACK
+# define ll_security_inode_init_security(inode, dir, name, value, len, \
+                                        initxattrs, dentry)           \
+        security_inode_init_security(inode, dir, &((dentry)->d_name), \
+                                     initxattrs, dentry)
+#elif defined HAVE_SECURITY_IINITSEC_QSTR
+# define ll_security_inode_init_security(inode, dir, name, value, len, \
+                                        initxattrs, dentry)           \
+        security_inode_init_security(inode, dir, &((dentry)->d_name), \
+                                     name, value, len)
+#else /* !HAVE_SECURITY_IINITSEC_CALLBACK && !HAVE_SECURITY_IINITSEC_QSTR */
+# define ll_security_inode_init_security(inode, dir, name, value, len, \
+                                        initxattrs, dentry)           \
+        security_inode_init_security(inode, dir, name, value, len)
+#endif
+
+#ifndef bio_for_each_segment_all /* since kernel version 3.9 */
+#ifdef HAVE_BVEC_ITER
+#define bio_for_each_segment_all(bv, bio, it) \
+       for (it = 0, bv = (bio)->bi_io_vec; it < (bio)->bi_vcnt; it++, bv++)
+#else
+#define bio_for_each_segment_all(bv, bio, it) bio_for_each_segment(bv, bio, it)
+#endif
+#endif
+
+#ifdef HAVE_PID_NS_FOR_CHILDREN
+# define ll_task_pid_ns(task)  ((task)->nsproxy->pid_ns_for_children)
+#else
+# define ll_task_pid_ns(task)  ((task)->nsproxy->pid_ns)
+#endif
+
+#ifdef HAVE_FULL_NAME_HASH_3ARGS
+# define ll_full_name_hash(salt, name, len) full_name_hash(salt, name, len)
+#else
+# define ll_full_name_hash(salt, name, len) full_name_hash(name, len)
+#endif
+
+#ifdef HAVE_STRUCT_POSIX_ACL_XATTR
+# define posix_acl_xattr_header struct posix_acl_xattr_header
+# define posix_acl_xattr_entry  struct posix_acl_xattr_entry
+# define GET_POSIX_ACL_XATTR_ENTRY(head) ((void *)((head) + 1))
+#else
+# define GET_POSIX_ACL_XATTR_ENTRY(head) ((head)->a_entries)
+#endif
+
+#ifdef HAVE_IOP_XATTR
+#ifdef HAVE_XATTR_HANDLER_FLAGS
+#define ll_setxattr     generic_setxattr
+#define ll_getxattr     generic_getxattr
+#define ll_removexattr  generic_removexattr
+#else
+int ll_setxattr(struct dentry *dentry, const char *name,
+               const void *value, size_t size, int flags);
+ssize_t ll_getxattr(struct dentry *dentry, const char *name,
+                   void *buf, size_t buf_size);
+int ll_removexattr(struct dentry *dentry, const char *name);
+#endif /* ! HAVE_XATTR_HANDLER_FLAGS */
+#endif /* HAVE_IOP_XATTR */
+
+#ifndef HAVE_VFS_SETXATTR
+const struct xattr_handler *get_xattr_type(const char *name);
+
+static inline int
+__vfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
+              const void *value, size_t size, int flags)
+{
+# ifdef HAVE_XATTR_HANDLER_FLAGS
+       const struct xattr_handler *handler;
+       int rc;
+
+       handler = get_xattr_type(name);
+       if (!handler)
+               return -EOPNOTSUPP;
+
+#  if defined(HAVE_XATTR_HANDLER_INODE_PARAM)
+       rc = handler->set(handler, dentry, inode, name, value, size, flags);
+#  elif defined(HAVE_XATTR_HANDLER_SIMPLIFIED)
+       rc = handler->set(handler, dentry, name, value, size, flags);
+#  else
+       rc = handler->set(dentry, name, value, size, flags, handler->flags);
+#  endif /* !HAVE_XATTR_HANDLER_INODE_PARAM */
+       return rc;
+# else /* !HAVE_XATTR_HANDLER_FLAGS */
+       return ll_setxattr(dentry, name, value, size, flags);
+# endif /* HAVE_XATTR_HANDLER_FLAGS */
+}
+#endif /* HAVE_VFS_SETXATTR */
+
+#ifdef HAVE_IOP_SET_ACL
+#ifdef CONFIG_FS_POSIX_ACL
+#ifndef HAVE_POSIX_ACL_UPDATE_MODE
+static inline int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
+                         struct posix_acl **acl)
+{
+       umode_t mode = inode->i_mode;
+       int error;
+
+       error = posix_acl_equiv_mode(*acl, &mode);
+       if (error < 0)
+               return error;
+       if (error == 0)
+               *acl = NULL;
+       if (!in_group_p(inode->i_gid) &&
+           !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+               mode &= ~S_ISGID;
+       *mode_p = mode;
+       return 0;
+}
+#endif /* HAVE_POSIX_ACL_UPDATE_MODE */
+#endif
+#endif
+
+#ifndef HAVE_IOV_ITER_TRUNCATE
+static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
+{
+       if (i->count > count)
+               i->count = count;
+}
+#endif
+
+#ifndef HAVE_IS_SXID
+static inline bool is_sxid(umode_t mode)
+{
+       return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
+}
+#endif
+
+#ifndef IS_NOSEC
+#define IS_NOSEC(inode)        (!is_sxid(inode->i_mode))
+#endif
+
+/*
+ * mount MS_* flags split from superblock SB_* flags
+ * if the SB_* flags are not available use the MS_* flags
+ */
+#if !defined(SB_RDONLY) && defined(MS_RDONLY)
+# define SB_RDONLY MS_RDONLY
+#endif
+#if !defined(SB_ACTIVE) && defined(MS_ACTIVE)
+# define SB_ACTIVE MS_ACTIVE
+#endif
+#if !defined(SB_NOSEC) && defined(MS_NOSEC)
+# define SB_NOSEC MS_NOSEC
+#endif
+#if !defined(SB_POSIXACL) && defined(MS_POSIXACL)
+# define SB_POSIXACL MS_POSIXACL
+#endif
+#if !defined(SB_NODIRATIME) && defined(MS_NODIRATIME)
+# define SB_NODIRATIME MS_NODIRATIME
+#endif
+
+#ifndef HAVE_FILE_OPERATIONS_READ_WRITE_ITER
+static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
+{
+       i->count = count;
+}
+
+static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
+{
+       return (struct iovec) {
+               .iov_base = iter->iov->iov_base + iter->iov_offset,
+               .iov_len = min(iter->count,
+                              iter->iov->iov_len - iter->iov_offset),
+       };
+}
+
+#define iov_for_each(iov, iter, start)                                 \
+       for (iter = (start);                                            \
+            (iter).count && ((iov = iov_iter_iovec(&(iter))), 1);      \
+            iov_iter_advance(&(iter), (iov).iov_len))
+
+static inline ssize_t
+generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+       struct iovec iov;
+       struct iov_iter i;
+       ssize_t bytes = 0;
+
+       iov_for_each(iov, i, *iter) {
+               ssize_t res;
+
+               res = generic_file_aio_read(iocb, &iov, 1, iocb->ki_pos);
+               if (res <= 0) {
+                       if (bytes == 0)
+                               bytes = res;
+                       break;
+               }
+
+               bytes += res;
+               if (res < iov.iov_len)
+                       break;
+       }
+
+       if (bytes > 0)
+               iov_iter_advance(iter, bytes);
+       return bytes;
+}
+
+static inline ssize_t
+__generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+       struct iovec iov;
+       struct iov_iter i;
+       ssize_t bytes = 0;
+
+       /* Since LLITE updates file size at the end of I/O in
+        * vvp_io_commit_write(), append write has to be done in atomic when
+        * there are multiple segments because otherwise each iteration to
+        * __generic_file_aio_write() will see original file size */
+       if (unlikely(iocb->ki_filp->f_flags & O_APPEND && iter->nr_segs > 1)) {
+               struct iovec *iov_copy;
+               int count = 0;
+
+               OBD_ALLOC(iov_copy, sizeof(*iov_copy) * iter->nr_segs);
+               if (!iov_copy)
+                       return -ENOMEM;
+
+               iov_for_each(iov, i, *iter)
+                       iov_copy[count++] = iov;
+
+               bytes = __generic_file_aio_write(iocb, iov_copy, count,
+                                                &iocb->ki_pos);
+               OBD_FREE(iov_copy, sizeof(*iov_copy) * iter->nr_segs);
+
+               if (bytes > 0)
+                       iov_iter_advance(iter, bytes);
+               return bytes;
+       }
+
+       iov_for_each(iov, i, *iter) {
+               ssize_t res;
+
+               res = __generic_file_aio_write(iocb, &iov, 1, &iocb->ki_pos);
+               if (res <= 0) {
+                       if (bytes == 0)
+                               bytes = res;
+                       break;
+               }
+
+               bytes += res;
+               if (res < iov.iov_len)
+                       break;
+       }
+
+       if (bytes > 0)
+               iov_iter_advance(iter, bytes);
+       return bytes;
+}
+#endif /* HAVE_FILE_OPERATIONS_READ_WRITE_ITER */
+
+static inline void __user *get_vmf_address(struct vm_fault *vmf)
+{
+#ifdef HAVE_VM_FAULT_ADDRESS
+       return (void __user *)vmf->address;
+#else
+       return vmf->virtual_address;
+#endif
+}
+
+#ifdef HAVE_VM_OPS_USE_VM_FAULT_ONLY
+# define ll_filemap_fault(vma, vmf) filemap_fault(vmf)
+#else
+# define ll_filemap_fault(vma, vmf) filemap_fault(vma, vmf)
+#endif
+
+#ifndef HAVE_CURRENT_TIME
+static inline struct timespec current_time(struct inode *inode)
+{
+       return CURRENT_TIME;
+}
+#endif
+
+#ifndef time_after32
+/**
+ * time_after32 - compare two 32-bit relative times
+ * @a: the time which may be after @b
+ * @b: the time which may be before @a
+ *
+ * time_after32(a, b) returns true if the time @a is after time @b.
+ * time_before32(b, a) returns true if the time @b is before time @a.
+ *
+ * Similar to time_after(), compare two 32-bit timestamps for relative
+ * times.  This is useful for comparing 32-bit seconds values that can't
+ * be converted to 64-bit values (e.g. due to disk format or wire protocol
+ * issues) when it is known that the times are less than 68 years apart.
+ */
+#define time_after32(a, b)     ((s32)((u32)(b) - (u32)(a)) < 0)
+#define time_before32(b, a)    time_after32(a, b)
+
+#endif
+
+#ifndef __GFP_COLD
+#define __GFP_COLD 0
+#endif
+
+#ifndef alloc_workqueue
+#define alloc_workqueue(name, flags, max_active) create_workqueue(name)
+#endif
+
+#ifndef smp_store_mb
+#define smp_store_mb(var, value)       set_mb(var, value)
+#endif
+
+#ifndef READ_ONCE
+#define READ_ONCE ACCESS_ONCE
+#endif
+
+#if IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)
+static inline unsigned short blk_integrity_interval(struct blk_integrity *bi)
+{
+#ifdef HAVE_INTERVAL_EXP_BLK_INTEGRITY
+       return bi->interval_exp ? 1 << bi->interval_exp : 0;
+#elif defined(HAVE_INTERVAL_BLK_INTEGRITY)
+       return bi->interval;
+#else
+       return bi->sector_size;
+#endif /* !HAVE_INTERVAL_EXP_BLK_INTEGRITY */
+}
+
+static inline const char *blk_integrity_name(struct blk_integrity *bi)
+{
+#ifdef HAVE_INTERVAL_EXP_BLK_INTEGRITY
+       return bi->profile->name;
+#else
+       return bi->name;
+#endif
+}
+
+static inline unsigned int bip_size(struct bio_integrity_payload *bip)
+{
+#ifdef HAVE_BIP_ITER_BIO_INTEGRITY_PAYLOAD
+       return bip->bip_iter.bi_size;
+#else
+       return bip->bip_size;
+#endif
+}
+#else /* !CONFIG_BLK_DEV_INTEGRITY */
+static inline unsigned short blk_integrity_interval(struct blk_integrity *bi)
+{
+       return 0;
+}
+static inline const char *blk_integrity_name(struct blk_integrity *bi)
+{
+       /* gcc8 dislikes when strcmp() is called against NULL */
+       return "";
+}
+#endif /* !CONFIG_BLK_DEV_INTEGRITY */
+
+#ifndef INTEGRITY_FLAG_READ
+#define INTEGRITY_FLAG_READ BLK_INTEGRITY_VERIFY
+#endif
+
+#ifndef INTEGRITY_FLAG_WRITE
+#define INTEGRITY_FLAG_WRITE BLK_INTEGRITY_GENERATE
+#endif
+
+static inline bool bdev_integrity_enabled(struct block_device *bdev, int rw)
+{
+#if IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)
+       struct blk_integrity *bi = bdev_get_integrity(bdev);
+
+       if (bi == NULL)
+               return false;
+
+#ifdef HAVE_INTERVAL_EXP_BLK_INTEGRITY
+       if (rw == 0 && bi->profile->verify_fn != NULL &&
+           (bi->flags & INTEGRITY_FLAG_READ))
+               return true;
+
+       if (rw == 1 && bi->profile->generate_fn != NULL &&
+           (bi->flags & INTEGRITY_FLAG_WRITE))
+               return true;
+#else
+       if (rw == 0 && bi->verify_fn != NULL &&
+           (bi->flags & INTEGRITY_FLAG_READ))
+               return true;
+
+       if (rw == 1 && bi->generate_fn != NULL &&
+           (bi->flags & INTEGRITY_FLAG_WRITE))
+               return true;
+#endif /* !HAVE_INTERVAL_EXP_BLK_INTEGRITY */
+#endif /* !CONFIG_BLK_DEV_INTEGRITY */
+
+       return false;
+}
+
+#ifdef HAVE_PAGEVEC_INIT_ONE_PARAM
+#define ll_pagevec_init(pvec, n) pagevec_init(pvec)
+#else
+#define ll_pagevec_init(pvec, n) pagevec_init(pvec, n)
+#endif
+
+#ifdef HAVE_I_PAGES
+#define page_tree i_pages
+#else
+#define i_pages tree_lock
+#define xa_lock_irq(lockp) spin_lock_irq(lockp)
+#define xa_unlock_irq(lockp) spin_unlock_irq(lockp)
+#endif
+
+#ifndef KMEM_CACHE_USERCOPY
+#define kmem_cache_create_usercopy(name, size, align, flags, useroffset, \
+                                  usersize, ctor)                       \
+       kmem_cache_create(name, size, align, flags, ctor)
+#endif
+
 #endif /* _LUSTRE_COMPAT_H */