romfs: do not use mtd->get_unmapped_area directly

Remove direct usage of mtd->get_unmapped_area. Instead, just call
'mtd_get_unmapped_area()' which will return -EOPNOTSUPP if the function
is not implemented, and then test for this code.

We also translate -EOPNOTSUPP to -ENOSYS because this return code is
probably part of the kernel ABI which we do not want to break.

Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 13 insertions, 15 deletions

diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index d5168e8e7dcb..e1a7779dd3cb 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -28,9 +28,10 @@ static unsigned long romfs_get_unmapped_area(struct file *file,
         struct inode *inode = file->f_mapping->host;
         struct mtd_info *mtd = inode->i_sb->s_mtd;
         unsigned long isize, offset, maxpages, lpages;
+        int ret;
 
         if (!mtd)
-                goto cant_map_directly;
+                return (unsigned long) -ENOSYS;
 
         /* the mapping mustn't extend beyond the EOF */
         lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
@@ -41,23 +42,20 @@ static unsigned long romfs_get_unmapped_area(struct file *file,
         if ((pgoff >= maxpages) || (maxpages - pgoff < lpages))
                 return (unsigned long) -EINVAL;
 
-        /* we need to call down to the MTD layer to do the actual mapping */
-        if (mtd->get_unmapped_area) {
-                if (addr != 0)
-                        return (unsigned long) -EINVAL;
-
-                if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
-                        return (unsigned long) -EINVAL;
+        if (addr != 0)
+                return (unsigned long) -EINVAL;
 
-                offset += ROMFS_I(inode)->i_dataoffset;
-                if (offset > mtd->size - len)
-                        return (unsigned long) -EINVAL;
+        if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
+                return (unsigned long) -EINVAL;
 
-                return mtd_get_unmapped_area(mtd, len, offset, flags);
-        }
+        offset += ROMFS_I(inode)->i_dataoffset;
+        if (offset > mtd->size - len)
+                return (unsigned long) -EINVAL;
 
-cant_map_directly:
-        return (unsigned long) -ENOSYS;
+        ret = mtd_get_unmapped_area(mtd, len, offset, flags);
+        if (ret == -EOPNOTSUPP)
+                ret = -ENOSYS;
+        return (unsigned long) ret;
 }
 
 /*