Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull second vfs pile from Al Viro:
 "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
  deadlock reproduced by xfstests 068), symlink and hardlink restriction
  patches, plus assorted cleanups and fixes.

  Note that another fsfreeze deadlock (emergency thaw one) is *not*
  dealt with - the series by Fernando conflicts a lot with Jan's, breaks
  userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
  for massive vfsmount leak; this is going to be handled next cycle.
  There probably will be another pull request, but that stuff won't be
  in it."

Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
  delousing target_core_file a bit
  Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
  fs: Remove old freezing mechanism
  ext2: Implement freezing
  btrfs: Convert to new freezing mechanism
  nilfs2: Convert to new freezing mechanism
  ntfs: Convert to new freezing mechanism
  fuse: Convert to new freezing mechanism
  gfs2: Convert to new freezing mechanism
  ocfs2: Convert to new freezing mechanism
  xfs: Convert to new freezing code
  ext4: Convert to new freezing mechanism
  fs: Protect write paths by sb_start_write - sb_end_write
  fs: Skip atime update on frozen filesystem
  fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
  fs: Improve filesystem freezing handling
  switch the protection of percpu_counter list to spinlock
  nfsd: Push mnt_want_write() outside of i_mutex
  btrfs: Push mnt_want_write() outside of i_mutex
  fat: Push mnt_want_write() outside of i_mutex
  ...

5 files changed, 30 insertions, 15 deletions

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 7602783d7f41..46a1f6d75104 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1971,6 +1971,7 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd,
 {
         struct inode *inode = file->f_path.dentry->d_inode;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+        int ret;
 
         if ((cmd == OCFS2_IOC_RESVSP || cmd == OCFS2_IOC_RESVSP64) &&
             !ocfs2_writes_unwritten_extents(osb))
@@ -1985,7 +1986,12 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd,
         if (!(file->f_mode & FMODE_WRITE))
                 return -EBADF;
 
-        return __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0);
+        ret = mnt_want_write_file(file);
+        if (ret)
+                return ret;
+        ret = __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0);
+        mnt_drop_write_file(file);
+        return ret;
 }
 
 static long ocfs2_fallocate(struct file *file, int mode, loff_t offset,
@@ -2261,7 +2267,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
         if (iocb->ki_left == 0)
                 return 0;
 
-        vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+        sb_start_write(inode->i_sb);
 
         appending = file->f_flags & O_APPEND ? 1 : 0;
         direct_io = file->f_flags & O_DIRECT ? 1 : 0;
@@ -2436,6 +2442,7 @@ out_sems:
                 ocfs2_iocb_clear_sem_locked(iocb);
 
         mutex_unlock(&inode->i_mutex);
+        sb_end_write(inode->i_sb);
 
         if (written)
                 ret = written;
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index d96f7f81d8dd..f20edcbfe700 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -928,7 +928,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 if (get_user(new_clusters, (int __user *)arg))
                         return -EFAULT;
 
-                return ocfs2_group_extend(inode, new_clusters);
+                status = mnt_want_write_file(filp);
+                if (status)
+                        return status;
+                status = ocfs2_group_extend(inode, new_clusters);
+                mnt_drop_write_file(filp);
+                return status;
         case OCFS2_IOC_GROUP_ADD:
         case OCFS2_IOC_GROUP_ADD64:
                 if (!capable(CAP_SYS_RESOURCE))
@@ -937,7 +942,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 if (copy_from_user(&input, (int __user *) arg, sizeof(input)))
                         return -EFAULT;
 
-                return ocfs2_group_add(inode, &input);
+                status = mnt_want_write_file(filp);
+                if (status)
+                        return status;
+                status = ocfs2_group_add(inode, &input);
+                mnt_drop_write_file(filp);
+                return status;
         case OCFS2_IOC_REFLINK:
                 if (copy_from_user(&args, argp, sizeof(args)))
                         return -EFAULT;
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 0a42ae96dca7..2dd36af79e26 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -355,11 +355,14 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb, int max_buffs)
         if (journal_current_handle())
                 return jbd2_journal_start(journal, max_buffs);
 
+        sb_start_intwrite(osb->sb);
+
         down_read(&osb->journal->j_trans_barrier);
 
         handle = jbd2_journal_start(journal, max_buffs);
         if (IS_ERR(handle)) {
                 up_read(&osb->journal->j_trans_barrier);
+                sb_end_intwrite(osb->sb);
 
                 mlog_errno(PTR_ERR(handle));
 
@@ -388,8 +391,10 @@ int ocfs2_commit_trans(struct ocfs2_super *osb,
         if (ret < 0)
                 mlog_errno(ret);
 
-        if (!nested)
+        if (!nested) {
                 up_read(&journal->j_trans_barrier);
+                sb_end_intwrite(osb->sb);
+        }
 
         return ret;
 }
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
index 9cd41083e991..d150372fd81d 100644
--- a/fs/ocfs2/mmap.c
+++ b/fs/ocfs2/mmap.c
@@ -136,6 +136,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         sigset_t oldset;
         int ret;
 
+        sb_start_pagefault(inode->i_sb);
         ocfs2_block_signals(&oldset);
 
         /*
@@ -165,6 +166,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 out:
         ocfs2_unblock_signals(&oldset);
+        sb_end_pagefault(inode->i_sb);
         return ret;
 }
 
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 9f32d7cbb7a3..30a055049e16 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4466,20 +4466,11 @@ int ocfs2_reflink_ioctl(struct inode *inode,
                 goto out_dput;
         }
 
-        error = mnt_want_write(new_path.mnt);
-        if (error) {
-                mlog_errno(error);
-                goto out_dput;
-        }
-
         error = ocfs2_vfs_reflink(old_path.dentry,
                                   new_path.dentry->d_inode,
                                   new_dentry, preserve);
-        mnt_drop_write(new_path.mnt);
 out_dput:
-        dput(new_dentry);
-        mutex_unlock(&new_path.dentry->d_inode->i_mutex);
-        path_put(&new_path);
+        done_path_create(&new_path, new_dentry);
 out:
         path_put(&old_path);