GFS2: Add "top dir" flag support

This patch adds support for the "top dir" flag. Currently this is unused
but a subsequent patch is planned which will add support for the
Orlov allocation policy when allocating subdirectories in a parent
with this flag set.

In order to ensure backward compatible behaviour, mkfs.gfs2 does
not currently tag the root directory with this flag, it must always be
set manually.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 26e2905070ed..6fbf3cbd974d 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -142,6 +142,7 @@ static const u32 fsflags_to_gfs2[32] = {
         [7] = GFS2_DIF_NOATIME,
         [12] = GFS2_DIF_EXHASH,
         [14] = GFS2_DIF_INHERIT_JDATA,
+        [17] = GFS2_DIF_TOPDIR,
 };
 
 static const u32 gfs2_to_fsflags[32] = {
@@ -150,6 +151,7 @@ static const u32 gfs2_to_fsflags[32] = {
         [gfs2fl_AppendOnly] = FS_APPEND_FL,
         [gfs2fl_NoAtime] = FS_NOATIME_FL,
         [gfs2fl_ExHash] = FS_INDEX_FL,
+        [gfs2fl_TopLevel] = FS_TOPDIR_FL,
         [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
 };
 
@@ -203,6 +205,7 @@ void gfs2_set_inode_flags(struct inode *inode)
                              GFS2_DIF_NOATIME|                  \
                              GFS2_DIF_SYNC|                     \
                              GFS2_DIF_SYSTEM|                   \
+                             GFS2_DIF_TOPDIR|                   \
                              GFS2_DIF_INHERIT_JDATA)
 
 /**
@@ -298,6 +301,7 @@ static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 
         gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
         if (!S_ISDIR(inode->i_mode)) {
+                gfsflags &= ~GFS2_DIF_TOPDIR;
                 if (gfsflags & GFS2_DIF_INHERIT_JDATA)
                         gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
                 return do_gfs2_set_flags(filp, gfsflags, ~0);
diff --git a/include/linux/gfs2_ondisk.h b/include/linux/gfs2_ondisk.h
index fa98bdb073b9..e8ccf6ff3b4d 100644
--- a/include/linux/gfs2_ondisk.h
+++ b/include/linux/gfs2_ondisk.h
@@ -214,6 +214,7 @@ enum {
         gfs2fl_NoAtime          = 7,
         gfs2fl_Sync             = 8,
         gfs2fl_System           = 9,
+        gfs2fl_TopLevel         = 10,
         gfs2fl_TruncInProg      = 29,
         gfs2fl_InheritDirectio  = 30,
         gfs2fl_InheritJdata     = 31,
@@ -230,8 +231,9 @@ enum {
 #define GFS2_DIF_NOATIME                0x00000080
 #define GFS2_DIF_SYNC                   0x00000100
 #define GFS2_DIF_SYSTEM                 0x00000200 /* New in gfs2 */
+#define GFS2_DIF_TOPDIR                 0x00000400 /* New in gfs2 */
 #define GFS2_DIF_TRUNC_IN_PROG          0x20000000 /* New in gfs2 */
-#define GFS2_DIF_INHERIT_DIRECTIO       0x40000000
+#define GFS2_DIF_INHERIT_DIRECTIO       0x40000000 /* only in gfs1 */
 #define GFS2_DIF_INHERIT_JDATA          0x80000000
 
 struct gfs2_dinode {