Define a new superblock field for more feature bits. Take the last

feature bit in sb_versionnum to use to indicate that the new feature
bit field is to be used.
Add new superblock fields for new feature bits.

diff --git a/db/sb.c b/db/sb.c
index 6500d1f809c429ed58108adf3938e32dc328678a..67ec56051f4785d375cbdd6da0372e1090b25f6c 100644 (file)
--- a/db/sb.c
+++ b/db/sb.c
@@ -121,6 +121,7 @@ const field_t       sb_flds[] = {
        { "logsectlog", FLDT_UINT8D, OI(OFF(logsectlog)), C1, 0, TYP_NONE },
        { "logsectsize", FLDT_UINT16D, OI(OFF(logsectsize)), C1, 0, TYP_NONE },
        { "logsunit", FLDT_UINT32D, OI(OFF(logsunit)), C1, 0, TYP_NONE },
+       { "features2", FLDT_UINT32X, OI(OFF(features2)), C1, 0, TYP_NONE },
        { NULL }
 };
 

diff --git a/include/xfs_sb.h b/include/xfs_sb.h
index 9a8bc968cc088ab4af6839c9a02cde6d71e81416..9e0adf4c48a767c9e0c9f2ed5ad28464d2bc6953 100644 (file)
--- a/include/xfs_sb.h
+++ b/include/xfs_sb.h
@@ -60,6 +60,7 @@ struct xfs_mount;
 #define XFS_SB_VERSION_SECTORBIT       0x0800
 #define        XFS_SB_VERSION_EXTFLGBIT        0x1000
 #define        XFS_SB_VERSION_DIRV2BIT         0x2000
+#define        XFS_SB_VERSION_MOREBITSBIT      0x8000
 #define        XFS_SB_VERSION_OKSASHFBITS      \
        (XFS_SB_VERSION_EXTFLGBIT | \
         XFS_SB_VERSION_DIRV2BIT)
@@ -80,17 +81,46 @@ struct xfs_mount;
        (XFS_SB_VERSION_NUMBITS | \
         XFS_SB_VERSION_OKREALFBITS | \
         XFS_SB_VERSION_OKSASHFBITS)
-#define XFS_SB_VERSION_MKFS(ia,dia,extflag,dirv2,na,sflag)     \
-       (((ia) || (dia) || (extflag) || (dirv2) || (na) || (sflag)) ? \
+#define XFS_SB_VERSION_MKFS(ia,dia,extflag,dirv2,na,sflag,morebits)    \
+       (((ia) || (dia) || (extflag) || (dirv2) || (na) || (sflag) || \
+         (morebits)) ? \
                (XFS_SB_VERSION_4 | \
                 ((ia) ? XFS_SB_VERSION_ALIGNBIT : 0) | \
                 ((dia) ? XFS_SB_VERSION_DALIGNBIT : 0) | \
                 ((extflag) ? XFS_SB_VERSION_EXTFLGBIT : 0) | \
                 ((dirv2) ? XFS_SB_VERSION_DIRV2BIT : 0) | \
                 ((na) ? XFS_SB_VERSION_LOGV2BIT : 0) | \
-                ((sflag) ? XFS_SB_VERSION_SECTORBIT : 0)) : \
+                ((sflag) ? XFS_SB_VERSION_SECTORBIT : 0) | \
+                ((morebits) ? XFS_SB_VERSION_MOREBITSBIT : 0)) : \
                XFS_SB_VERSION_1)
 
+/*
+ * There are two words to hold XFS "feature" bits: the original
+ * word, sb_versionnum, and sb_features2.  Whenever a bit is set in
+ * sb_features2, the feature bit XFS_SB_VERSION_MOREBITSBIT must be set.
+ *
+ * These defines represent bits in sb_features2.
+ */
+#define XFS_SB_VERSION2_REALFBITS      0x00ffffff      /* Mask: features */
+#define XFS_SB_VERSION2_RESERVED1BIT   0x00000001
+#define XFS_SB_VERSION2_SASHFBITS      0xff000000      /* Mask: features that
+                                                          require changing
+                                                          PROM and SASH */
+
+#define        XFS_SB_VERSION2_OKREALFBITS     \
+       (0)
+#define        XFS_SB_VERSION2_OKSASHFBITS     \
+       (0)
+#define XFS_SB_VERSION2_OKREALBITS     \
+       (XFS_SB_VERSION2_OKREALFBITS |  \
+        XFS_SB_VERSION2_OKSASHFBITS )
+
+/*
+ * mkfs macro to set up sb_features2 word
+ */
+#define        XFS_SB_VERSION2_MKFS(xyz)       \
+       ((xyz) ? 0 : 0)
+
 typedef struct xfs_sb
 {
        __uint32_t      sb_magicnum;    /* magic number == XFS_SB_MAGIC */
@@ -146,6 +176,7 @@ typedef struct xfs_sb
        __uint8_t       sb_logsectlog;  /* log2 of the log sector size */
        __uint16_t      sb_logsectsize; /* sector size for the log, bytes */
        __uint32_t      sb_logsunit;    /* stripe unit size for the log */
+       __uint32_t      sb_features2;   /* additonal feature bits */
 } xfs_sb_t;
 
 /*
@@ -164,6 +195,7 @@ 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_FIELDCOUNT
 } xfs_sb_field_t;
 
@@ -217,8 +249,11 @@ int xfs_sb_good_version(xfs_sb_t *sbp);
 #define        XFS_SB_GOOD_VERSION_INT(sbp)    \
        ((((sbp)->sb_versionnum >= XFS_SB_VERSION_1) && \
          ((sbp)->sb_versionnum <= XFS_SB_VERSION_3)) || \
-        ((XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
-         !((sbp)->sb_versionnum & ~XFS_SB_VERSION_OKREALBITS)
+          ((XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
+           !(((sbp)->sb_versionnum & ~XFS_SB_VERSION_OKREALBITS) && \
+             ((sbp)->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) && \
+             ((sbp)->sb_features2 & ~XFS_SB_VERSION2_OKREALBITS))
+
 #ifdef __KERNEL__
 #define        XFS_SB_GOOD_VERSION(sbp)        \
        (XFS_SB_GOOD_VERSION_INT(sbp) && \
@@ -453,6 +488,25 @@ int xfs_sb_version_hassector(xfs_sb_t *sbp);
        ((sbp)->sb_versionnum & XFS_SB_VERSION_SECTORBIT))
 #endif
 
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_SB_VERSION_HASMOREBITSBIT)
+int xfs_sb_version_hasmorebits(xfs_sb_t *sbp);
+#define XFS_SB_VERSION_HASMOREBITS(sbp)        xfs_sb_version_hasmorebits(sbp)
+#else
+#define XFS_SB_VERSION_HASMOREBITS(sbp)        \
+       ((XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
+        ((sbp)->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT))
+#endif
+
+/*
+ * sb_features2 bit version macros.
+ *
+ * For example, for a bit defined as XFS_SB_VERSION2_YBIT, has a macro:
+ *
+ * SB_VERSION_HASYBIT(xfs_sb_t *sbp)
+ *     ((XFS_SB_VERSION_HASMOREBITS(sbp) &&
+ *      ((sbp)->sb_versionnum & XFS_SB_VERSION2_YBIT)
+ */
+
 /*
  * end of superblock version macros
  */

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index dcf26e4b533fdba45012b3daa0b886abebbac4b5..86b0f3e4f31c23db10432a8e57b4867b8a2d9268 100644 (file)
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -1931,8 +1931,8 @@ an AG size that is one stripe unit smaller, for example %llu.\n"),
        sbp->sb_versionnum =
                XFS_SB_VERSION_MKFS(iaflag, dsunit != 0, extent_flagging,
                        dirversion == 2, logversion == 2,
-                       (sectorsize != BBSIZE || lsectorsize != BBSIZE));
-
+                       (sectorsize != BBSIZE || lsectorsize != BBSIZE), 0);
+       sbp->sb_features2 = XFS_SB_VERSION2_MKFS(0);
        /*
         * Zero out the first 68k in on the device, to obliterate any old 
         * filesystem signatures out there.  This should take care of