NTFS: Use i_size_read() in fs/ntfs/attrib.c::ntfs_attr_set().

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>

3 files changed, 7 insertions, 2 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 1d2ad15f1533..9c4e78a8e4b1 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -31,6 +31,7 @@ ToDo/Notes:
           compiled without debug.  This avoids a possible denial of service
           attack.  Thanks to Carl-Daniel Hailfinger from SuSE for pointing this
           out.
+        - Use i_size_read() in fs/ntfs/attrib.c::ntfs_attr_set().
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 
diff --git a/fs/ntfs/Makefile b/fs/ntfs/Makefile
index 7b66381a0b0f..f8c97d41226b 100644
--- a/fs/ntfs/Makefile
+++ b/fs/ntfs/Makefile
@@ -6,7 +6,7 @@ ntfs-objs := aops.o attrib.o collate.o compress.o debug.o dir.o file.o \
              index.o inode.o mft.o mst.o namei.o runlist.o super.o sysctl.o \
              unistr.o upcase.o
 
-EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.22\"
+EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.23-WIP\"
 
 ifeq ($(CONFIG_NTFS_DEBUG),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 1ff7f90a18b0..7d668466dcd7 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -1127,6 +1127,10 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size)
  * byte offset @ofs inside the attribute with the constant byte @val.
  *
  * This function is effectively like memset() applied to an ntfs attribute.
+ * Note thie function actually only operates on the page cache pages belonging
+ * to the ntfs attribute and it marks them dirty after doing the memset().
+ * Thus it relies on the vm dirty page write code paths to cause the modified
+ * pages to be written to the mft record/disk.
  *
  * Return 0 on success and -errno on error.  An error code of -ESPIPE means
  * that @ofs + @cnt were outside the end of the attribute and no write was
@@ -1155,7 +1159,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
         end = ofs + cnt;
         end_ofs = end & ~PAGE_CACHE_MASK;
         /* If the end is outside the inode size return -ESPIPE. */
-        if (unlikely(end > VFS_I(ni)->i_size)) {
+        if (unlikely(end > i_size_read(VFS_I(ni)))) {
                 ntfs_error(vol->sb, "Request exceeds end of attribute.");
                 return -ESPIPE;
         }