Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6

32 files changed, 246 insertions, 220 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index d7312825592b..c509123bea49 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1744,10 +1744,10 @@ config ROOT_NFS
           If you want your Linux box to mount its whole root file system (the
           one containing the directory /) from some other computer over the
           net via NFS (presumably because your box doesn't have a hard disk),
-          say Y. Read <file:Documentation/nfsroot.txt> for details. It is
-          likely that in this case, you also want to say Y to "Kernel level IP
-          autoconfiguration" so that your box can discover its network address
-          at boot time.
+          say Y. Read <file:Documentation/filesystems/nfsroot.txt> for
+          details. It is likely that in this case, you also want to say Y to
+          "Kernel level IP autoconfiguration" so that your box can discover
+          its network address at boot time.
 
           Most people say N here.
 
diff --git a/fs/aio.c b/fs/aio.c
index 6af921940622..228368610dfa 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -936,14 +936,6 @@ int aio_complete(struct kiocb *iocb, long res, long res2)
                 return 1;
         }
 
-        /*
-         * Check if the user asked us to deliver the result through an
-         * eventfd. The eventfd_signal() function is safe to be called
-         * from IRQ context.
-         */
-        if (!IS_ERR(iocb->ki_eventfd))
-                eventfd_signal(iocb->ki_eventfd, 1);
-
         info = &ctx->ring_info;
 
         /* add a completion event to the ring buffer.
@@ -992,6 +984,15 @@ int aio_complete(struct kiocb *iocb, long res, long res2)
         kunmap_atomic(ring, KM_IRQ1);
 
         pr_debug("added to ring %p at [%lu]\n", iocb, tail);
+
+        /*
+         * Check if the user asked us to deliver the result through an
+         * eventfd. The eventfd_signal() function is safe to be called
+         * from IRQ context.
+         */
+        if (!IS_ERR(iocb->ki_eventfd))
+                eventfd_signal(iocb->ki_eventfd, 1);
+
 put_rq:
         /* everything turned out well, dispose of the aiocb. */
         ret = __aio_put_req(ctx, iocb);
@@ -1790,6 +1791,7 @@ asmlinkage long sys_io_getevents(aio_context_t ctx_id,
                 put_ioctx(ioctx);
         }
 
+        asmlinkage_protect(5, ret, ctx_id, min_nr, nr, events, timeout);
         return ret;
 }
 
diff --git a/fs/buffer.c b/fs/buffer.c
index 98196327ddf0..39ff14403d13 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1181,7 +1181,20 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
 void mark_buffer_dirty(struct buffer_head *bh)
 {
         WARN_ON_ONCE(!buffer_uptodate(bh));
-        if (!buffer_dirty(bh) && !test_set_buffer_dirty(bh))
+
+        /*
+         * Very *carefully* optimize the it-is-already-dirty case.
+         *
+         * Don't let the final "is it dirty" escape to before we
+         * perhaps modified the buffer.
+         */
+        if (buffer_dirty(bh)) {
+                smp_mb();
+                if (buffer_dirty(bh))
+                        return;
+        }
+
+        if (!test_set_buffer_dirty(bh))
                 __set_page_dirty(bh->b_page, page_mapping(bh->b_page), 0);
 }
 
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 29683645fa0a..5f4023678251 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -340,16 +340,23 @@ static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
 
         if (inode->i_nlink > 0)
                 drop_nlink(inode);
-        hfsplus_delete_inode(inode);
-        if (inode->i_ino != cnid && !inode->i_nlink) {
-                if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {
-                        res = hfsplus_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
-                        if (!res)
-                                hfsplus_delete_inode(inode);
+        if (inode->i_ino == cnid)
+                clear_nlink(inode);
+        if (!inode->i_nlink) {
+                if (inode->i_ino != cnid) {
+                        HFSPLUS_SB(sb).file_count--;
+                        if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {
+                                res = hfsplus_delete_cat(inode->i_ino,
+                                                         HFSPLUS_SB(sb).hidden_dir,
+                                                         NULL);
+                                if (!res)
+                                        hfsplus_delete_inode(inode);
+                        } else
+                                inode->i_flags |= S_DEAD;
                 } else
-                        inode->i_flags |= S_DEAD;
+                        hfsplus_delete_inode(inode);
         } else
-                clear_nlink(inode);
+                HFSPLUS_SB(sb).file_count--;
         inode->i_ctime = CURRENT_TIME_SEC;
         mark_inode_dirty(inode);
 
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index f9c5dd6f4b64..dcc2734e0b5d 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -129,7 +129,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
         struct inode *inode = mapping->host;
         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-        uint32_t pageofs = pos & (PAGE_CACHE_SIZE - 1);
+        uint32_t pageofs = index << PAGE_CACHE_SHIFT;
         int ret = 0;
 
         pg = __grab_cache_page(mapping, index);
diff --git a/fs/locks.c b/fs/locks.c
index d83fab1b77b5..43c0af21a0c5 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1801,17 +1801,21 @@ again:
         if (error)
                 goto out;
 
-        for (;;) {
-                error = vfs_lock_file(filp, cmd, file_lock, NULL);
-                if (error != -EAGAIN || cmd == F_SETLK)
-                        break;
-                error = wait_event_interruptible(file_lock->fl_wait,
-                                !file_lock->fl_next);
-                if (!error)
-                        continue;
+        if (filp->f_op && filp->f_op->lock != NULL)
+                error = filp->f_op->lock(filp, cmd, file_lock);
+        else {
+                for (;;) {
+                        error = posix_lock_file(filp, file_lock, NULL);
+                        if (error != -EAGAIN || cmd == F_SETLK)
+                                break;
+                        error = wait_event_interruptible(file_lock->fl_wait,
+                                        !file_lock->fl_next);
+                        if (!error)
+                                continue;
 
-                locks_delete_block(file_lock);
-                break;
+                        locks_delete_block(file_lock);
+                        break;
+                }
         }
 
         /*
@@ -1925,17 +1929,21 @@ again:
         if (error)
                 goto out;
 
-        for (;;) {
-                error = vfs_lock_file(filp, cmd, file_lock, NULL);
-                if (error != -EAGAIN || cmd == F_SETLK64)
-                        break;
-                error = wait_event_interruptible(file_lock->fl_wait,
-                                !file_lock->fl_next);
-                if (!error)
-                        continue;
+        if (filp->f_op && filp->f_op->lock != NULL)
+                error = filp->f_op->lock(filp, cmd, file_lock);
+        else {
+                for (;;) {
+                        error = posix_lock_file(filp, file_lock, NULL);
+                        if (error != -EAGAIN || cmd == F_SETLK64)
+                                break;
+                        error = wait_event_interruptible(file_lock->fl_wait,
+                                        !file_lock->fl_next);
+                        if (!error)
+                                continue;
 
-                locks_delete_block(file_lock);
-                break;
+                        locks_delete_block(file_lock);
+                        break;
+                }
         }
 
         /*
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index ef57a5ae5904..5d2e9d9a4e28 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -64,7 +64,11 @@ const struct file_operations nfs_file_operations = {
         .write          = do_sync_write,
         .aio_read       = nfs_file_read,
         .aio_write      = nfs_file_write,
+#ifdef CONFIG_MMU
         .mmap           = nfs_file_mmap,
+#else
+        .mmap           = generic_file_mmap,
+#endif
         .open           = nfs_file_open,
         .flush          = nfs_file_flush,
         .release        = nfs_file_release,
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index a4c7cf2bff3a..6f88d7c77ac9 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -506,6 +506,7 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str
                 ctx->cred = get_rpccred(cred);
                 ctx->state = NULL;
                 ctx->lockowner = current->files;
+                ctx->flags = 0;
                 ctx->error = 0;
                 ctx->dir_cookie = 0;
                 atomic_set(&ctx->count, 1);
diff --git a/fs/open.c b/fs/open.c
index a4b12022edaa..3fa4e4ffce4c 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -335,7 +335,7 @@ asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length)
 {
         long ret = do_sys_ftruncate(fd, length, 1);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, fd, length);
         return ret;
 }
 
@@ -350,7 +350,7 @@ asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length)
 {
         long ret = do_sys_ftruncate(fd, length, 0);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(2, ret, fd, length);
         return ret;
 }
 #endif
@@ -1067,7 +1067,7 @@ asmlinkage long sys_open(const char __user *filename, int flags, int mode)
 
         ret = do_sys_open(AT_FDCWD, filename, flags, mode);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(3, ret, filename, flags, mode);
         return ret;
 }
 
@@ -1081,7 +1081,7 @@ asmlinkage long sys_openat(int dfd, const char __user *filename, int flags,
 
         ret = do_sys_open(dfd, filename, flags, mode);
         /* avoid REGPARM breakage on x86: */
-        prevent_tail_call(ret);
+        asmlinkage_protect(4, ret, dfd, filename, flags, mode);
         return ret;
 }
 
diff --git a/fs/signalfd.c b/fs/signalfd.c
index cb2b63ae0bf4..8ead0db35933 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -111,9 +111,14 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
                 err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
                 err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
                 break;
-        default: /* this is just in case for now ... */
+        default:
+                /*
+                 * This case catches also the signals queued by sigqueue().
+                 */
                 err |= __put_user(kinfo->si_pid, &uinfo->ssi_pid);
                 err |= __put_user(kinfo->si_uid, &uinfo->ssi_uid);
+                err |= __put_user((long) kinfo->si_ptr, &uinfo->ssi_ptr);
+                err |= __put_user(kinfo->si_int, &uinfo->ssi_int);
                 break;
         }
 
diff --git a/fs/splice.c b/fs/splice.c
index a861bb318ac8..eeb1a86a7014 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -370,8 +370,10 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                          * for an in-flight io page
                          */
                         if (flags & SPLICE_F_NONBLOCK) {
-                                if (TestSetPageLocked(page))
+                                if (TestSetPageLocked(page)) {
+                                        error = -EAGAIN;
                                         break;
+                                }
                         } else
                                 lock_page(page);
 
@@ -479,9 +481,8 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
                                  struct pipe_inode_info *pipe, size_t len,
                                  unsigned int flags)
 {
-        ssize_t spliced;
-        int ret;
         loff_t isize, left;
+        int ret;
 
         isize = i_size_read(in->f_mapping->host);
         if (unlikely(*ppos >= isize))
@@ -491,29 +492,9 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
         if (unlikely(left < len))
                 len = left;
 
-        ret = 0;
-        spliced = 0;
-        while (len && !spliced) {
-                ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
-
-                if (ret < 0)
-                        break;
-                else if (!ret) {
-                        if (spliced)
-                                break;
-                        if (flags & SPLICE_F_NONBLOCK) {
-                                ret = -EAGAIN;
-                                break;
-                        }
-                }
-
+        ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
+        if (ret > 0)
                 *ppos += ret;
-                len -= ret;
-                spliced += ret;
-        }
-
-        if (spliced)
-                return spliced;
 
         return ret;
 }
diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index a9952e490ac9..f34bd010eb51 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -732,7 +732,7 @@ xfs_ioctl(
                  * Only allow the sys admin to reserve space unless
                  * unwritten extents are enabled.
                  */
-                if (!XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb) &&
+                if (!xfs_sb_version_hasextflgbit(&mp->m_sb) &&
                     !capable(CAP_SYS_ADMIN))
                         return -EPERM;
 
diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index 1f3da5b8657b..8e9c5ae6504d 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -1405,13 +1405,13 @@ xfs_qm_qino_alloc(
 #if defined(DEBUG) && defined(XFS_LOUD_RECOVERY)
                 unsigned oldv = mp->m_sb.sb_versionnum;
 #endif
-                ASSERT(!XFS_SB_VERSION_HASQUOTA(&mp->m_sb));
+                ASSERT(!xfs_sb_version_hasquota(&mp->m_sb));
                 ASSERT((sbfields & (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
                                    XFS_SB_GQUOTINO | XFS_SB_QFLAGS)) ==
                        (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
                         XFS_SB_GQUOTINO | XFS_SB_QFLAGS));
 
-                XFS_SB_VERSION_ADDQUOTA(&mp->m_sb);
+                xfs_sb_version_addquota(&mp->m_sb);
                 mp->m_sb.sb_uquotino = NULLFSINO;
                 mp->m_sb.sb_gquotino = NULLFSINO;
 
@@ -1954,7 +1954,7 @@ xfs_qm_init_quotainos(
         /*
          * Get the uquota and gquota inodes
          */
-        if (XFS_SB_VERSION_HASQUOTA(&mp->m_sb)) {
+        if (xfs_sb_version_hasquota(&mp->m_sb)) {
                 if (XFS_IS_UQUOTA_ON(mp) &&
                     mp->m_sb.sb_uquotino != NULLFSINO) {
                         ASSERT(mp->m_sb.sb_uquotino > 0);
diff --git a/fs/xfs/quota/xfs_qm_bhv.c b/fs/xfs/quota/xfs_qm_bhv.c
index 97bb32937585..f4f6c4c861d7 100644
--- a/fs/xfs/quota/xfs_qm_bhv.c
+++ b/fs/xfs/quota/xfs_qm_bhv.c
@@ -118,7 +118,7 @@ xfs_qm_newmount(
         *quotaflags = 0;
         *needquotamount = B_FALSE;
 
-        quotaondisk = XFS_SB_VERSION_HASQUOTA(&mp->m_sb) &&
+        quotaondisk = xfs_sb_version_hasquota(&mp->m_sb) &&
                                 (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT);
 
         if (quotaondisk) {
diff --git a/fs/xfs/quota/xfs_qm_syscalls.c b/fs/xfs/quota/xfs_qm_syscalls.c
index 2cc5886cfe85..d2b8be7e75f9 100644
--- a/fs/xfs/quota/xfs_qm_syscalls.c
+++ b/fs/xfs/quota/xfs_qm_syscalls.c
@@ -377,7 +377,7 @@ xfs_qm_scall_trunc_qfiles(
         if (!capable(CAP_SYS_ADMIN))
                 return XFS_ERROR(EPERM);
         error = 0;
-        if (!XFS_SB_VERSION_HASQUOTA(&mp->m_sb) || flags == 0) {
+        if (!xfs_sb_version_hasquota(&mp->m_sb) || flags == 0) {
                 qdprintk("qtrunc flags=%x m_qflags=%x\n", flags, mp->m_qflags);
                 return XFS_ERROR(EINVAL);
         }
@@ -522,7 +522,7 @@ xfs_qm_scall_getqstat(
         memset(out, 0, sizeof(fs_quota_stat_t));
 
         out->qs_version = FS_QSTAT_VERSION;
-        if (! XFS_SB_VERSION_HASQUOTA(&mp->m_sb)) {
+        if (!xfs_sb_version_hasquota(&mp->m_sb)) {
                 out->qs_uquota.qfs_ino = NULLFSINO;
                 out->qs_gquota.qfs_ino = NULLFSINO;
                 return (0);
diff --git a/fs/xfs/xfs_attr_leaf.c b/fs/xfs/xfs_attr_leaf.c
index b08e2a2a8add..96ba6aa4ed8c 100644
--- a/fs/xfs/xfs_attr_leaf.c
+++ b/fs/xfs/xfs_attr_leaf.c
@@ -227,10 +227,10 @@ STATIC void
 xfs_sbversion_add_attr2(xfs_mount_t *mp, xfs_trans_t *tp)
 {
         if ((mp->m_flags & XFS_MOUNT_ATTR2) &&
-            !(XFS_SB_VERSION_HASATTR2(&mp->m_sb))) {
+            !(xfs_sb_version_hasattr2(&mp->m_sb))) {
                 spin_lock(&mp->m_sb_lock);
-                if (!XFS_SB_VERSION_HASATTR2(&mp->m_sb)) {
-                        XFS_SB_VERSION_ADDATTR2(&mp->m_sb);
+                if (!xfs_sb_version_hasattr2(&mp->m_sb)) {
+                        xfs_sb_version_addattr2(&mp->m_sb);
                         spin_unlock(&mp->m_sb_lock);
                         xfs_mod_sb(tp, XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
                 } else
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 1c0a5a585a82..2def273855a2 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -4047,17 +4047,17 @@ xfs_bmap_add_attrfork(
                 xfs_trans_log_inode(tp, ip, logflags);
         if (error)
                 goto error2;
-        if (!XFS_SB_VERSION_HASATTR(&mp->m_sb) ||
-           (!XFS_SB_VERSION_HASATTR2(&mp->m_sb) && version == 2)) {
+        if (!xfs_sb_version_hasattr(&mp->m_sb) ||
+           (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2)) {
                 __int64_t sbfields = 0;
 
                 spin_lock(&mp->m_sb_lock);
-                if (!XFS_SB_VERSION_HASATTR(&mp->m_sb)) {
-                        XFS_SB_VERSION_ADDATTR(&mp->m_sb);
+                if (!xfs_sb_version_hasattr(&mp->m_sb)) {
+                        xfs_sb_version_addattr(&mp->m_sb);
                         sbfields |= XFS_SB_VERSIONNUM;
                 }
-                if (!XFS_SB_VERSION_HASATTR2(&mp->m_sb) && version == 2) {
-                        XFS_SB_VERSION_ADDATTR2(&mp->m_sb);
+                if (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2) {
+                        xfs_sb_version_addattr2(&mp->m_sb);
                         sbfields |= (XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
                 }
                 if (sbfields) {
@@ -5043,7 +5043,7 @@ xfs_bmapi(
                          * A wasdelay extent has been initialized, so
                          * shouldn't be flagged as unwritten.
                          */
-                        if (wr && XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb)) {
+                        if (wr && xfs_sb_version_hasextflgbit(&mp->m_sb)) {
                                 if (!wasdelay && (flags & XFS_BMAPI_PREALLOC))
                                         got.br_state = XFS_EXT_UNWRITTEN;
                         }
@@ -5483,7 +5483,7 @@ xfs_bunmapi(
                          * get rid of part of a realtime extent.
                          */
                         if (del.br_state == XFS_EXT_UNWRITTEN ||
-                            !XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb)) {
+                            !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
                                 /*
                                  * This piece is unwritten, or we're not
                                  * using unwritten extents.  Skip over it.
@@ -5535,7 +5535,7 @@ xfs_bunmapi(
                         } else if ((del.br_startoff == start &&
                                     (del.br_state == XFS_EXT_UNWRITTEN ||
                                      xfs_trans_get_block_res(tp) == 0)) ||
-                                   !XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb)) {
+                                   !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
                                 /*
                                  * Can't make it unwritten.  There isn't
                                  * a full extent here so just skip it.
diff --git a/fs/xfs/xfs_bmap_btree.h b/fs/xfs/xfs_bmap_btree.h
index 2d950e975918..cd0d4b4bb816 100644
--- a/fs/xfs/xfs_bmap_btree.h
+++ b/fs/xfs/xfs_bmap_btree.h
@@ -120,7 +120,7 @@ typedef enum {
  * Extent state and extent format macros.
  */
 #define XFS_EXTFMT_INODE(x)     \
-        (XFS_SB_VERSION_HASEXTFLGBIT(&((x)->i_mount->m_sb)) ? \
+        (xfs_sb_version_hasextflgbit(&((x)->i_mount->m_sb)) ? \
                 XFS_EXTFMT_HASSTATE : XFS_EXTFMT_NOSTATE)
 #define ISUNWRITTEN(x)  ((x)->br_state == XFS_EXT_UNWRITTEN)
 
diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index be7c4251fa61..e92e73f0e6af 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -49,7 +49,7 @@ void
 xfs_dir_mount(
         xfs_mount_t     *mp)
 {
-        ASSERT(XFS_SB_VERSION_HASDIRV2(&mp->m_sb));
+        ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
         ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
                XFS_MAX_BLOCKSIZE);
         mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index eadc1591c795..d3a0f538d6a6 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -77,36 +77,36 @@ xfs_fs_geometry(
         if (new_version >= 3) {
                 geo->version = XFS_FSOP_GEOM_VERSION;
                 geo->flags =
-                        (XFS_SB_VERSION_HASATTR(&mp->m_sb) ?
+                        (xfs_sb_version_hasattr(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_ATTR : 0) |
-                        (XFS_SB_VERSION_HASNLINK(&mp->m_sb) ?
+                        (xfs_sb_version_hasnlink(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_NLINK : 0) |
-                        (XFS_SB_VERSION_HASQUOTA(&mp->m_sb) ?
+                        (xfs_sb_version_hasquota(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_QUOTA : 0) |
-                        (XFS_SB_VERSION_HASALIGN(&mp->m_sb) ?
+                        (xfs_sb_version_hasalign(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_IALIGN : 0) |
-                        (XFS_SB_VERSION_HASDALIGN(&mp->m_sb) ?
+                        (xfs_sb_version_hasdalign(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_DALIGN : 0) |
-                        (XFS_SB_VERSION_HASSHARED(&mp->m_sb) ?
+                        (xfs_sb_version_hasshared(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_SHARED : 0) |
-                        (XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb) ?
+                        (xfs_sb_version_hasextflgbit(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_EXTFLG : 0) |
-                        (XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
+                        (xfs_sb_version_hasdirv2(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
-                        (XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
+                        (xfs_sb_version_hassector(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
                         (xfs_sb_version_haslazysbcount(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
-                        (XFS_SB_VERSION_HASATTR2(&mp->m_sb) ?
+                        (xfs_sb_version_hasattr2(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_ATTR2 : 0);
-                geo->logsectsize = XFS_SB_VERSION_HASSECTOR(&mp->m_sb) ?
+                geo->logsectsize = xfs_sb_version_hassector(&mp->m_sb) ?
                                 mp->m_sb.sb_logsectsize : BBSIZE;
                 geo->rtsectsize = mp->m_sb.sb_blocksize;
                 geo->dirblocksize = mp->m_dirblksize;
         }
         if (new_version >= 4) {
                 geo->flags |=
-                        (XFS_SB_VERSION_HASLOGV2(&mp->m_sb) ?
+                        (xfs_sb_version_haslogv2(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_LOGV2 : 0);
                 geo->logsunit = mp->m_sb.sb_logsunit;
         }
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index db9d5fa600af..5a146cb22980 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -191,7 +191,7 @@ xfs_ialloc_ag_alloc(
                         ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
                         args.alignment = args.mp->m_dalign;
                         isaligned = 1;
-                } else if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
+                } else if (xfs_sb_version_hasalign(&args.mp->m_sb) &&
                            args.mp->m_sb.sb_inoalignmt >=
                            XFS_B_TO_FSBT(args.mp,
                                 XFS_INODE_CLUSTER_SIZE(args.mp)))
@@ -230,7 +230,7 @@ xfs_ialloc_ag_alloc(
                 args.agbno = be32_to_cpu(agi->agi_root);
                 args.fsbno = XFS_AGB_TO_FSB(args.mp,
                                 be32_to_cpu(agi->agi_seqno), args.agbno);
-                if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
+                if (xfs_sb_version_hasalign(&args.mp->m_sb) &&
                         args.mp->m_sb.sb_inoalignmt >=
                         XFS_B_TO_FSBT(args.mp, XFS_INODE_CLUSTER_SIZE(args.mp)))
                                 args.alignment = args.mp->m_sb.sb_inoalignmt;
@@ -271,7 +271,7 @@ xfs_ialloc_ag_alloc(
          * use the old version so that old kernels will continue to be
          * able to use the file system.
          */
-        if (XFS_SB_VERSION_HASNLINK(&args.mp->m_sb))
+        if (xfs_sb_version_hasnlink(&args.mp->m_sb))
                 version = XFS_DINODE_VERSION_2;
         else
                 version = XFS_DINODE_VERSION_1;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index a550546a7083..f43a6e01d68f 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1147,7 +1147,7 @@ xfs_ialloc(
          * the inode version number now.  This way we only do the conversion
          * here rather than here and in the flush/logging code.
          */
-        if (XFS_SB_VERSION_HASNLINK(&tp->t_mountp->m_sb) &&
+        if (xfs_sb_version_hasnlink(&tp->t_mountp->m_sb) &&
             ip->i_d.di_version == XFS_DINODE_VERSION_1) {
                 ip->i_d.di_version = XFS_DINODE_VERSION_2;
                 /*
@@ -3434,9 +3434,9 @@ xfs_iflush_int(
          * has been updated, then make the conversion permanent.
          */
         ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1 ||
-               XFS_SB_VERSION_HASNLINK(&mp->m_sb));
+               xfs_sb_version_hasnlink(&mp->m_sb));
         if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
-                if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
+                if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                         /*
                          * Convert it back.
                          */
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 034ca7202295..2c775b4ae9e6 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -296,9 +296,9 @@ xfs_inode_item_format(
          */
         mp = ip->i_mount;
         ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1 ||
-               XFS_SB_VERSION_HASNLINK(&mp->m_sb));
+               xfs_sb_version_hasnlink(&mp->m_sb));
         if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
-                if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
+                if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                         /*
                          * Convert it back.
                          */
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 658aab6b1bbf..f615e04364f4 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -45,7 +45,7 @@ xfs_internal_inum(
         xfs_ino_t       ino)
 {
         return (ino == mp->m_sb.sb_rbmino || ino == mp->m_sb.sb_rsumino ||
-                (XFS_SB_VERSION_HASQUOTA(&mp->m_sb) &&
+                (xfs_sb_version_hasquota(&mp->m_sb) &&
                  (ino == mp->m_sb.sb_uquotino || ino == mp->m_sb.sb_gquotino)));
 }
 
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index a75edca1860f..31f2b04f2c97 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1090,7 +1090,7 @@ xlog_get_iclog_buffer_size(xfs_mount_t	*mp,
                         size >>= 1;
                 }
 
-                if (XFS_SB_VERSION_HASLOGV2(&mp->m_sb)) {
+                if (xfs_sb_version_haslogv2(&mp->m_sb)) {
                         /* # headers = size / 32K
                          * one header holds cycles from 32K of data
                          */
@@ -1186,13 +1186,13 @@ xlog_alloc_log(xfs_mount_t	*mp,
         log->l_grant_reserve_cycle = 1;
         log->l_grant_write_cycle = 1;
 
-        if (XFS_SB_VERSION_HASSECTOR(&mp->m_sb)) {
+        if (xfs_sb_version_hassector(&mp->m_sb)) {
                 log->l_sectbb_log = mp->m_sb.sb_logsectlog - BBSHIFT;
                 ASSERT(log->l_sectbb_log <= mp->m_sectbb_log);
                 /* for larger sector sizes, must have v2 or external log */
                 ASSERT(log->l_sectbb_log == 0 ||
                         log->l_logBBstart == 0 ||
-                        XFS_SB_VERSION_HASLOGV2(&mp->m_sb));
+                        xfs_sb_version_haslogv2(&mp->m_sb));
                 ASSERT(mp->m_sb.sb_logsectlog >= BBSHIFT);
         }
         log->l_sectbb_mask = (1 << log->l_sectbb_log) - 1;
@@ -1247,7 +1247,7 @@ xlog_alloc_log(xfs_mount_t	*mp,
                 memset(head, 0, sizeof(xlog_rec_header_t));
                 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
                 head->h_version = cpu_to_be32(
-                        XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? 2 : 1);
+                        xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
                 head->h_size = cpu_to_be32(log->l_iclog_size);
                 /* new fields */
                 head->h_fmt = cpu_to_be32(XLOG_FMT);
@@ -1402,7 +1402,7 @@ xlog_sync(xlog_t		*log,
         int             roundoff;       /* roundoff to BB or stripe */
         int             split = 0;      /* split write into two regions */
         int             error;
-        int             v2 = XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb);
+        int             v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
 
         XFS_STATS_INC(xs_log_writes);
         ASSERT(iclog->ic_refcnt == 0);
@@ -2881,7 +2881,7 @@ xlog_state_switch_iclogs(xlog_t		*log,
         log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
 
         /* Round up to next log-sunit */
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) &&
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
             log->l_mp->m_sb.sb_logsunit > 1) {
                 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
                 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
@@ -3334,7 +3334,7 @@ xlog_ticket_get(xlog_t		*log,
         unit_bytes += sizeof(xlog_op_header_t) * num_headers;
 
         /* for roundoff padding for transaction data and one for commit record */
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) &&
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
             log->l_mp->m_sb.sb_logsunit > 1) {
                 /* log su roundoff */
                 unit_bytes += 2*log->l_mp->m_sb.sb_logsunit;
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index e008233ee249..c6244cc733c0 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -49,10 +49,10 @@ struct xfs_mount;
 #define XLOG_HEADER_SIZE        512
 
 #define XLOG_REC_SHIFT(log) \
-        BTOBB(1 << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
+        BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
          XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
 #define XLOG_TOTAL_REC_SHIFT(log) \
-        BTOBB(XLOG_MAX_ICLOGS << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
+        BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
          XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
 
 
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index b82d5d4d2462..b2b70eba282c 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -478,7 +478,7 @@ xlog_find_verify_log_record(
          * reset last_blk.  Only when last_blk points in the middle of a log
          * record do we update last_blk.
          */
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                 uint    h_size = be32_to_cpu(head->h_size);
 
                 xhdrs = h_size / XLOG_HEADER_CYCLE_SIZE;
@@ -888,7 +888,7 @@ xlog_find_tail(
          * unmount record if there is one, so we pass the lsn of the
          * unmount record rather than the block after it.
          */
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                 int     h_size = be32_to_cpu(rhead->h_size);
                 int     h_version = be32_to_cpu(rhead->h_version);
 
@@ -1101,7 +1101,7 @@ xlog_add_record(
         recp->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
         recp->h_cycle = cpu_to_be32(cycle);
         recp->h_version = cpu_to_be32(
-                        XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? 2 : 1);
+                        xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
         recp->h_lsn = cpu_to_be64(xlog_assign_lsn(cycle, block));
         recp->h_tail_lsn = cpu_to_be64(xlog_assign_lsn(tail_cycle, tail_block));
         recp->h_fmt = cpu_to_be32(XLOG_FMT);
@@ -3348,7 +3348,7 @@ xlog_pack_data(
                 dp += BBSIZE;
         }
 
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                 xhdr = (xlog_in_core_2_t *)&iclog->ic_header;
                 for ( ; i < BTOBB(size); i++) {
                         j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
@@ -3388,7 +3388,7 @@ xlog_unpack_data_checksum(
                             be32_to_cpu(rhead->h_chksum), chksum);
                     cmn_err(CE_DEBUG,
 "XFS: Disregard message if filesystem was created with non-DEBUG kernel");
-                    if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+                    if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                             cmn_err(CE_DEBUG,
                                 "XFS: LogR this is a LogV2 filesystem\n");
                     }
@@ -3415,7 +3415,7 @@ xlog_unpack_data(
                 dp += BBSIZE;
         }
 
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                 xhdr = (xlog_in_core_2_t *)rhead;
                 for ( ; i < BTOBB(be32_to_cpu(rhead->h_len)); i++) {
                         j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
@@ -3494,7 +3494,7 @@ xlog_do_recovery_pass(
          * Read the header of the tail block and get the iclog buffer size from
          * h_size.  Use this to tell how many sectors make up the log header.
          */
-        if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
                 /*
                  * When using variable length iclogs, read first sector of
                  * iclog header and extract the header size from it.  Get a
@@ -3838,7 +3838,7 @@ xlog_do_recover(
         sbp = &log->l_mp->m_sb;
         xfs_sb_from_disk(sbp, XFS_BUF_TO_SBP(bp));
         ASSERT(sbp->sb_magicnum == XFS_SB_MAGIC);
-        ASSERT(XFS_SB_GOOD_VERSION(sbp));
+        ASSERT(xfs_sb_good_version(sbp));
         xfs_buf_relse(bp);
 
         /* We've re-read the superblock so re-initialize per-cpu counters */
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 6409b3762995..8ed164eb9544 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -44,7 +44,7 @@
 #include "xfs_quota.h"
 #include "xfs_fsops.h"
 
-STATIC void     xfs_mount_log_sbunit(xfs_mount_t *, __int64_t);
+STATIC void     xfs_mount_log_sb(xfs_mount_t *, __int64_t);
 STATIC int      xfs_uuid_mount(xfs_mount_t *);
 STATIC void     xfs_uuid_unmount(xfs_mount_t *mp);
 STATIC void     xfs_unmountfs_wait(xfs_mount_t *);
@@ -119,6 +119,7 @@ static const struct {
     { offsetof(xfs_sb_t, sb_logsectsize),0 },
     { offsetof(xfs_sb_t, sb_logsunit),   0 },
     { offsetof(xfs_sb_t, sb_features2),  0 },
+    { offsetof(xfs_sb_t, sb_bad_features2), 0 },
     { sizeof(xfs_sb_t),                  0 }
 };
 
@@ -225,7 +226,7 @@ xfs_mount_validate_sb(
                 return XFS_ERROR(EWRONGFS);
         }
 
-        if (!XFS_SB_GOOD_VERSION(sbp)) {
+        if (!xfs_sb_good_version(sbp)) {
                 xfs_fs_mount_cmn_err(flags, "bad version");
                 return XFS_ERROR(EWRONGFS);
         }
@@ -300,7 +301,7 @@ xfs_mount_validate_sb(
         /*
          * Version 1 directory format has never worked on Linux.
          */
-        if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) {
+        if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
                 xfs_fs_mount_cmn_err(flags,
                         "file system using version 1 directory format");
                 return XFS_ERROR(ENOSYS);
@@ -449,6 +450,7 @@ xfs_sb_from_disk(
         to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
         to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
         to->sb_features2 = be32_to_cpu(from->sb_features2);
+        to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
 }
 
 /*
@@ -781,7 +783,7 @@ xfs_update_alignment(xfs_mount_t *mp, int mfsi_flags, __uint64_t *update_flags)
                  * Update superblock with new values
                  * and log changes
                  */
-                if (XFS_SB_VERSION_HASDALIGN(sbp)) {
+                if (xfs_sb_version_hasdalign(sbp)) {
                         if (sbp->sb_unit != mp->m_dalign) {
                                 sbp->sb_unit = mp->m_dalign;
                                 *update_flags |= XFS_SB_UNIT;
@@ -792,7 +794,7 @@ xfs_update_alignment(xfs_mount_t *mp, int mfsi_flags, __uint64_t *update_flags)
                         }
                 }
         } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
-                    XFS_SB_VERSION_HASDALIGN(&mp->m_sb)) {
+                    xfs_sb_version_hasdalign(&mp->m_sb)) {
                         mp->m_dalign = sbp->sb_unit;
                         mp->m_swidth = sbp->sb_width;
         }
@@ -869,7 +871,7 @@ xfs_set_rw_sizes(xfs_mount_t *mp)
 STATIC void
 xfs_set_inoalignment(xfs_mount_t *mp)
 {
-        if (XFS_SB_VERSION_HASALIGN(&mp->m_sb) &&
+        if (xfs_sb_version_hasalign(&mp->m_sb) &&
             mp->m_sb.sb_inoalignmt >=
             XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
                 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
@@ -970,6 +972,38 @@ xfs_mountfs(
         xfs_mount_common(mp, sbp);
 
         /*
+         * Check for a mismatched features2 values.  Older kernels
+         * read & wrote into the wrong sb offset for sb_features2
+         * on some platforms due to xfs_sb_t not being 64bit size aligned
+         * when sb_features2 was added, which made older superblock
+         * reading/writing routines swap it as a 64-bit value.
+         *
+         * For backwards compatibility, we make both slots equal.
+         *
+         * If we detect a mismatched field, we OR the set bits into the
+         * existing features2 field in case it has already been modified; we
+         * don't want to lose any features.  We then update the bad location
+         * with the ORed value so that older kernels will see any features2
+         * flags, and mark the two fields as needing updates once the
+         * transaction subsystem is online.
+         */
+        if (xfs_sb_has_mismatched_features2(sbp)) {
+                cmn_err(CE_WARN,
+                        "XFS: correcting sb_features alignment problem");
+                sbp->sb_features2 |= sbp->sb_bad_features2;
+                sbp->sb_bad_features2 = sbp->sb_features2;
+                update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
+
+                /*
+                 * Re-check for ATTR2 in case it was found in bad_features2
+                 * slot.
+                 */
+                if (xfs_sb_version_hasattr2(&mp->m_sb))
+                        mp->m_flags |= XFS_MOUNT_ATTR2;
+
+        }
+
+        /*
          * Check if sb_agblocks is aligned at stripe boundary
          * If sb_agblocks is NOT aligned turn off m_dalign since
          * allocator alignment is within an ag, therefore ag has
@@ -1159,11 +1193,10 @@ xfs_mountfs(
         }
 
         /*
-         * If fs is not mounted readonly, then update the superblock
-         * unit and width changes.
+         * If fs is not mounted readonly, then update the superblock changes.
          */
         if (update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY))
-                xfs_mount_log_sbunit(mp, update_flags);
+                xfs_mount_log_sb(mp, update_flags);
 
         /*
          * Initialise the XFS quota management subsystem for this mount
@@ -1875,16 +1908,18 @@ xfs_uuid_unmount(
 
 /*
  * Used to log changes to the superblock unit and width fields which could
- * be altered by the mount options. Only the first superblock is updated.
+ * be altered by the mount options, as well as any potential sb_features2
+ * fixup. Only the first superblock is updated.
  */
 STATIC void
-xfs_mount_log_sbunit(
+xfs_mount_log_sb(
         xfs_mount_t     *mp,
         __int64_t       fields)
 {
         xfs_trans_t     *tp;
 
-        ASSERT(fields & (XFS_SB_UNIT|XFS_SB_WIDTH|XFS_SB_UUID));
+        ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
+                         XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2));
 
         tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
         if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h
index 94660b1a6ccc..d904efe7f871 100644
--- a/fs/xfs/xfs_sb.h
+++ b/fs/xfs/xfs_sb.h
@@ -89,6 +89,7 @@ struct xfs_mount;
 
 /*
  * Superblock - in core version.  Must match the ondisk version below.
+ * Must be padded to 64 bit alignment.
  */
 typedef struct xfs_sb {
         __uint32_t      sb_magicnum;    /* magic number == XFS_SB_MAGIC */
@@ -145,10 +146,21 @@ typedef struct xfs_sb {
         __uint16_t      sb_logsectsize; /* sector size for the log, bytes */
         __uint32_t      sb_logsunit;    /* stripe unit size for the log */
         __uint32_t      sb_features2;   /* additional feature bits */
+
+        /*
+         * bad features2 field as a result of failing to pad the sb
+         * structure to 64 bits. Some machines will be using this field
+         * for features2 bits. Easiest just to mark it bad and not use
+         * it for anything else.
+         */
+        __uint32_t      sb_bad_features2;
+
+        /* must be padded to 64 bit alignment */
 } xfs_sb_t;
 
 /*
- * Superblock - on disk version.  Must match the in core version below.
+ * Superblock - on disk version.  Must match the in core version above.
+ * Must be padded to 64 bit alignment.
  */
 typedef struct xfs_dsb {
         __be32          sb_magicnum;    /* magic number == XFS_SB_MAGIC */
@@ -205,6 +217,15 @@ typedef struct xfs_dsb {
         __be16          sb_logsectsize; /* sector size for the log, bytes */
         __be32          sb_logsunit;    /* stripe unit size for the log */
         __be32          sb_features2;   /* additional feature bits */
+        /*
+         * bad features2 field as a result of failing to pad the sb
+         * structure to 64 bits. Some machines will be using this field
+         * for features2 bits. Easiest just to mark it bad and not use
+         * it for anything else.
+         */
+        __be32  sb_bad_features2;
+
+        /* must be padded to 64 bit alignment */
 } xfs_dsb_t;
 
 /*
@@ -223,7 +244,7 @@ typedef enum {
         XFS_SBS_GQUOTINO, XFS_SBS_QFLAGS, XFS_SBS_FLAGS, XFS_SBS_SHARED_VN,
         XFS_SBS_INOALIGNMT, XFS_SBS_UNIT, XFS_SBS_WIDTH, XFS_SBS_DIRBLKLOG,
         XFS_SBS_LOGSECTLOG, XFS_SBS_LOGSECTSIZE, XFS_SBS_LOGSUNIT,
-        XFS_SBS_FEATURES2,
+        XFS_SBS_FEATURES2, XFS_SBS_BAD_FEATURES2,
         XFS_SBS_FIELDCOUNT
 } xfs_sb_field_t;
 
@@ -248,13 +269,15 @@ typedef enum {
 #define XFS_SB_IFREE            XFS_SB_MVAL(IFREE)
 #define XFS_SB_FDBLOCKS         XFS_SB_MVAL(FDBLOCKS)
 #define XFS_SB_FEATURES2        XFS_SB_MVAL(FEATURES2)
+#define XFS_SB_BAD_FEATURES2    XFS_SB_MVAL(BAD_FEATURES2)
 #define XFS_SB_NUM_BITS         ((int)XFS_SBS_FIELDCOUNT)
 #define XFS_SB_ALL_BITS         ((1LL << XFS_SB_NUM_BITS) - 1)
 #define XFS_SB_MOD_BITS         \
         (XFS_SB_UUID | XFS_SB_ROOTINO | XFS_SB_RBMINO | XFS_SB_RSUMINO | \
          XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO | XFS_SB_GQUOTINO | \
          XFS_SB_QFLAGS | XFS_SB_SHARED_VN | XFS_SB_UNIT | XFS_SB_WIDTH | \
-         XFS_SB_ICOUNT | XFS_SB_IFREE | XFS_SB_FDBLOCKS | XFS_SB_FEATURES2)
+         XFS_SB_ICOUNT | XFS_SB_IFREE | XFS_SB_FDBLOCKS | XFS_SB_FEATURES2 | \
+         XFS_SB_BAD_FEATURES2)
 
 
 /*
@@ -271,7 +294,6 @@ typedef enum {
 
 #define XFS_SB_VERSION_NUM(sbp) ((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)
 
-#define XFS_SB_GOOD_VERSION(sbp)        xfs_sb_good_version(sbp)
 #ifdef __KERNEL__
 static inline int xfs_sb_good_version(xfs_sb_t *sbp)
 {
@@ -297,7 +319,15 @@ static inline int xfs_sb_good_version(xfs_sb_t *sbp)
 }
 #endif /* __KERNEL__ */
 
-#define XFS_SB_VERSION_TONEW(v) xfs_sb_version_tonew(v)
+/*
+ * Detect a mismatched features2 field.  Older kernels read/wrote
+ * this into the wrong slot, so to be safe we keep them in sync.
+ */
+static inline int xfs_sb_has_mismatched_features2(xfs_sb_t *sbp)
+{
+        return (sbp->sb_bad_features2 != sbp->sb_features2);
+}
+
 static inline unsigned xfs_sb_version_tonew(unsigned v)
 {
         return ((((v) == XFS_SB_VERSION_1) ? \
@@ -308,7 +338,6 @@ static inline unsigned xfs_sb_version_tonew(unsigned v)
                 XFS_SB_VERSION_4);
 }
 
-#define XFS_SB_VERSION_TOOLD(v) xfs_sb_version_toold(v)
 static inline unsigned xfs_sb_version_toold(unsigned v)
 {
         return (((v) & (XFS_SB_VERSION_QUOTABIT | XFS_SB_VERSION_ALIGNBIT)) ? \
@@ -320,7 +349,6 @@ static inline unsigned xfs_sb_version_toold(unsigned v)
                                 XFS_SB_VERSION_1)));
 }
 
-#define XFS_SB_VERSION_HASATTR(sbp)     xfs_sb_version_hasattr(sbp)
 static inline int xfs_sb_version_hasattr(xfs_sb_t *sbp)
 {
         return ((sbp)->sb_versionnum == XFS_SB_VERSION_2) || \
@@ -329,7 +357,6 @@ static inline int xfs_sb_version_hasattr(xfs_sb_t *sbp)
                   ((sbp)->sb_versionnum & XFS_SB_VERSION_ATTRBIT));
 }
 
-#define XFS_SB_VERSION_ADDATTR(sbp)     xfs_sb_version_addattr(sbp)
 static inline void xfs_sb_version_addattr(xfs_sb_t *sbp)
 {
         (sbp)->sb_versionnum = (((sbp)->sb_versionnum == XFS_SB_VERSION_1) ? \
@@ -339,7 +366,6 @@ static inline void xfs_sb_version_addattr(xfs_sb_t *sbp)
                         (XFS_SB_VERSION_4 | XFS_SB_VERSION_ATTRBIT)));
 }
 
-#define XFS_SB_VERSION_HASNLINK(sbp)    xfs_sb_version_hasnlink(sbp)
 static inline int xfs_sb_version_hasnlink(xfs_sb_t *sbp)
 {
         return ((sbp)->sb_versionnum == XFS_SB_VERSION_3) || \
@@ -347,7 +373,6 @@ static inline int xfs_sb_version_hasnlink(xfs_sb_t *sbp)
                   ((sbp)->sb_versionnum & XFS_SB_VERSION_NLINKBIT));
 }
 
-#define XFS_SB_VERSION_ADDNLINK(sbp)    xfs_sb_version_addnlink(sbp)
 static inline void xfs_sb_version_addnlink(xfs_sb_t *sbp)
 {
         (sbp)->sb_versionnum = ((sbp)->sb_versionnum <= XFS_SB_VERSION_2 ? \
@@ -355,115 +380,63 @@ static inline void xfs_sb_version_addnlink(xfs_sb_t *sbp)
                 ((sbp)->sb_versionnum | XFS_SB_VERSION_NLINKBIT));
 }
 
-#define XFS_SB_VERSION_HASQUOTA(sbp)    xfs_sb_version_hasquota(sbp)
 static inline int xfs_sb_version_hasquota(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_QUOTABIT);
 }
 
-#define XFS_SB_VERSION_ADDQUOTA(sbp)    xfs_sb_version_addquota(sbp)
 static inline void xfs_sb_version_addquota(xfs_sb_t *sbp)
 {
         (sbp)->sb_versionnum = \
                  (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4 ? \
                         ((sbp)->sb_versionnum | XFS_SB_VERSION_QUOTABIT) : \
-                        (XFS_SB_VERSION_TONEW((sbp)->sb_versionnum) | \
+                        (xfs_sb_version_tonew((sbp)->sb_versionnum) | \
                          XFS_SB_VERSION_QUOTABIT));
 }
 
-#define XFS_SB_VERSION_HASALIGN(sbp)    xfs_sb_version_hasalign(sbp)
 static inline int xfs_sb_version_hasalign(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_ALIGNBIT);
 }
 
-#define XFS_SB_VERSION_SUBALIGN(sbp)    xfs_sb_version_subalign(sbp)
-static inline void xfs_sb_version_subalign(xfs_sb_t *sbp)
-{
-        (sbp)->sb_versionnum = \
-         XFS_SB_VERSION_TOOLD((sbp)->sb_versionnum & ~XFS_SB_VERSION_ALIGNBIT);
-}
-
-#define XFS_SB_VERSION_HASDALIGN(sbp)   xfs_sb_version_hasdalign(sbp)
 static inline int xfs_sb_version_hasdalign(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_DALIGNBIT);
 }
 
-#define XFS_SB_VERSION_ADDDALIGN(sbp)   xfs_sb_version_adddalign(sbp)
-static inline int xfs_sb_version_adddalign(xfs_sb_t *sbp)
-{
-        return (sbp)->sb_versionnum = \
-                ((sbp)->sb_versionnum | XFS_SB_VERSION_DALIGNBIT);
-}
-
-#define XFS_SB_VERSION_HASSHARED(sbp)   xfs_sb_version_hasshared(sbp)
 static inline int xfs_sb_version_hasshared(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_SHAREDBIT);
 }
 
-#define XFS_SB_VERSION_ADDSHARED(sbp)   xfs_sb_version_addshared(sbp)
-static inline int xfs_sb_version_addshared(xfs_sb_t *sbp)
-{
-        return (sbp)->sb_versionnum = \
-                ((sbp)->sb_versionnum | XFS_SB_VERSION_SHAREDBIT);
-}
-
-#define XFS_SB_VERSION_SUBSHARED(sbp)   xfs_sb_version_subshared(sbp)
-static inline int xfs_sb_version_subshared(xfs_sb_t *sbp)
-{
-        return (sbp)->sb_versionnum = \
-                ((sbp)->sb_versionnum & ~XFS_SB_VERSION_SHAREDBIT);
-}
-
-#define XFS_SB_VERSION_HASDIRV2(sbp)    xfs_sb_version_hasdirv2(sbp)
 static inline int xfs_sb_version_hasdirv2(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
 }
 
-#define XFS_SB_VERSION_HASLOGV2(sbp)   xfs_sb_version_haslogv2(sbp)
 static inline int xfs_sb_version_haslogv2(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_LOGV2BIT);
 }
 
-#define XFS_SB_VERSION_HASEXTFLGBIT(sbp)        xfs_sb_version_hasextflgbit(sbp)
 static inline int xfs_sb_version_hasextflgbit(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT);
 }
 
-#define XFS_SB_VERSION_ADDEXTFLGBIT(sbp)        xfs_sb_version_addextflgbit(sbp)
-static inline int xfs_sb_version_addextflgbit(xfs_sb_t *sbp)
-{
-        return (sbp)->sb_versionnum = \
-                ((sbp)->sb_versionnum | XFS_SB_VERSION_EXTFLGBIT);
-}
-
-#define XFS_SB_VERSION_SUBEXTFLGBIT(sbp)        xfs_sb_version_subextflgbit(sbp)
-static inline int xfs_sb_version_subextflgbit(xfs_sb_t *sbp)
-{
-        return (sbp)->sb_versionnum = \
-                ((sbp)->sb_versionnum & ~XFS_SB_VERSION_EXTFLGBIT);
-}
-
-#define XFS_SB_VERSION_HASSECTOR(sbp)   xfs_sb_version_hassector(sbp)
 static inline int xfs_sb_version_hassector(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
                 ((sbp)->sb_versionnum & XFS_SB_VERSION_SECTORBIT);
 }
 
-#define XFS_SB_VERSION_HASMOREBITS(sbp) xfs_sb_version_hasmorebits(sbp)
 static inline int xfs_sb_version_hasmorebits(xfs_sb_t *sbp)
 {
         return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
@@ -476,24 +449,22 @@ static inline int xfs_sb_version_hasmorebits(xfs_sb_t *sbp)
  * For example, for a bit defined as XFS_SB_VERSION2_FUNBIT, has a macro:
  *
  * SB_VERSION_HASFUNBIT(xfs_sb_t *sbp)
- *      ((XFS_SB_VERSION_HASMOREBITS(sbp) &&
+ *      ((xfs_sb_version_hasmorebits(sbp) &&
  *       ((sbp)->sb_features2 & XFS_SB_VERSION2_FUNBIT)
  */
 
 static inline int xfs_sb_version_haslazysbcount(xfs_sb_t *sbp)
 {
-        return (XFS_SB_VERSION_HASMOREBITS(sbp) &&      \
+        return (xfs_sb_version_hasmorebits(sbp) &&      \
                 ((sbp)->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT));
 }
 
-#define XFS_SB_VERSION_HASATTR2(sbp)    xfs_sb_version_hasattr2(sbp)
 static inline int xfs_sb_version_hasattr2(xfs_sb_t *sbp)
 {
-        return (XFS_SB_VERSION_HASMOREBITS(sbp)) &&     \
+        return (xfs_sb_version_hasmorebits(sbp)) &&     \
                 ((sbp)->sb_features2 & XFS_SB_VERSION2_ATTR2BIT);
 }
 
-#define XFS_SB_VERSION_ADDATTR2(sbp)    xfs_sb_version_addattr2(sbp)
 static inline void xfs_sb_version_addattr2(xfs_sb_t *sbp)
 {
         ((sbp)->sb_versionnum = \
diff --git a/fs/xfs/xfs_utils.c b/fs/xfs/xfs_utils.c
index 45d740df53b7..18a85e746680 100644
--- a/fs/xfs/xfs_utils.c
+++ b/fs/xfs/xfs_utils.c
@@ -339,10 +339,10 @@ xfs_bump_ino_vers2(
         ip->i_d.di_onlink = 0;
         memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
         mp = tp->t_mountp;
-        if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
+        if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
                 spin_lock(&mp->m_sb_lock);
-                if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
-                        XFS_SB_VERSION_ADDNLINK(&mp->m_sb);
+                if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
+                        xfs_sb_version_addnlink(&mp->m_sb);
                         spin_unlock(&mp->m_sb_lock);
                         xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
                 } else {
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index 7321304a69cc..7094caff13cf 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -330,7 +330,7 @@ xfs_finish_flags(
         int                     ronly = (mp->m_flags & XFS_MOUNT_RDONLY);
 
         /* Fail a mount where the logbuf is smaller then the log stripe */
-        if (XFS_SB_VERSION_HASLOGV2(&mp->m_sb)) {
+        if (xfs_sb_version_haslogv2(&mp->m_sb)) {
                 if ((ap->logbufsize <= 0) &&
                     (mp->m_sb.sb_logsunit > XLOG_BIG_RECORD_BSIZE)) {
                         mp->m_logbsize = mp->m_sb.sb_logsunit;
@@ -349,9 +349,8 @@ xfs_finish_flags(
                 }
         }
 
-        if (XFS_SB_VERSION_HASATTR2(&mp->m_sb)) {
+        if (xfs_sb_version_hasattr2(&mp->m_sb))
                 mp->m_flags |= XFS_MOUNT_ATTR2;
-        }
 
         /*
          * prohibit r/w mounts of read-only filesystems
@@ -366,7 +365,7 @@ xfs_finish_flags(
          * check for shared mount.
          */
         if (ap->flags & XFSMNT_SHARED) {
-                if (!XFS_SB_VERSION_HASSHARED(&mp->m_sb))
+                if (!xfs_sb_version_hasshared(&mp->m_sb))
                         return XFS_ERROR(EINVAL);
 
                 /*
@@ -512,7 +511,7 @@ xfs_mount(
         if (!error && logdev && logdev != ddev) {
                 unsigned int    log_sector_size = BBSIZE;
 
-                if (XFS_SB_VERSION_HASSECTOR(&mp->m_sb))
+                if (xfs_sb_version_hassector(&mp->m_sb))
                         log_sector_size = mp->m_sb.sb_logsectsize;
                 error = xfs_setsize_buftarg(mp->m_logdev_targp,
                                             mp->m_sb.sb_blocksize,
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 51305242ff8c..64c5953feca4 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -4132,7 +4132,7 @@ xfs_free_file_space(
          * actually need to zero the extent edges.  Otherwise xfs_bunmapi
          * will take care of it for us.
          */
-        if (rt && !XFS_SB_VERSION_HASEXTFLGBIT(&mp->m_sb)) {
+        if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
                 nimap = 1;
                 error = xfs_bmapi(NULL, ip, startoffset_fsb,
                         1, 0, NULL, 0, &imap, &nimap, NULL, NULL);