[XFS] superblock endianess annotations

Creates a new xfs_dsb_t that is __be annotated and keeps xfs_sb_t for the
incore one. xfs_xlatesb is renamed to xfs_sb_to_disk and only handles the
incore -> disk conversion. A new helper xfs_sb_from_disk handles the other
direction and doesn't need the slightly hacky table-driven approach
because we only ever read the full sb from disk.

The handling of shared r/o filesystems has been buggy on little endian
system and fixing this required shuffling around of some code in that
area.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29477a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

1 files changed, 88 insertions, 46 deletions

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index eef27f21f9ab..f4daf1ec9931 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -407,37 +407,79 @@ xfs_initialize_perag(
         return index;
 }
 
+void
+xfs_sb_from_disk(
+        xfs_sb_t        *to,
+        xfs_dsb_t       *from)
+{
+        to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
+        to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
+        to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
+        to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
+        to->sb_rextents = be64_to_cpu(from->sb_rextents);
+        memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
+        to->sb_logstart = be64_to_cpu(from->sb_logstart);
+        to->sb_rootino = be64_to_cpu(from->sb_rootino);
+        to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
+        to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
+        to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
+        to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
+        to->sb_agcount = be32_to_cpu(from->sb_agcount);
+        to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
+        to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
+        to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
+        to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
+        to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
+        to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
+        memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
+        to->sb_blocklog = from->sb_blocklog;
+        to->sb_sectlog = from->sb_sectlog;
+        to->sb_inodelog = from->sb_inodelog;
+        to->sb_inopblog = from->sb_inopblog;
+        to->sb_agblklog = from->sb_agblklog;
+        to->sb_rextslog = from->sb_rextslog;
+        to->sb_inprogress = from->sb_inprogress;
+        to->sb_imax_pct = from->sb_imax_pct;
+        to->sb_icount = be64_to_cpu(from->sb_icount);
+        to->sb_ifree = be64_to_cpu(from->sb_ifree);
+        to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
+        to->sb_frextents = be64_to_cpu(from->sb_frextents);
+        to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
+        to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
+        to->sb_qflags = be16_to_cpu(from->sb_qflags);
+        to->sb_flags = from->sb_flags;
+        to->sb_shared_vn = from->sb_shared_vn;
+        to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
+        to->sb_unit = be32_to_cpu(from->sb_unit);
+        to->sb_width = be32_to_cpu(from->sb_width);
+        to->sb_dirblklog = from->sb_dirblklog;
+        to->sb_logsectlog = from->sb_logsectlog;
+        to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
+        to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
+        to->sb_features2 = be32_to_cpu(from->sb_features2);
+}
+
 /*
- * xfs_xlatesb
+ * Copy in core superblock to ondisk one.
  *
- *     data       - on disk version of sb
- *     sb         - a superblock
- *     dir        - conversion direction: <0 - convert sb to buf
- *                                        >0 - convert buf to sb
- *     fields     - which fields to copy (bitmask)
+ * The fields argument is mask of superblock fields to copy.
  */
 void
-xfs_xlatesb(
-        void            *data,
-        xfs_sb_t        *sb,
-        int             dir,
+xfs_sb_to_disk(
+        xfs_dsb_t       *to,
+        xfs_sb_t        *from,
         __int64_t       fields)
 {
-        xfs_caddr_t     buf_ptr;
-        xfs_caddr_t     mem_ptr;
+        xfs_caddr_t     to_ptr = (xfs_caddr_t)to;
+        xfs_caddr_t     from_ptr = (xfs_caddr_t)from;
         xfs_sb_field_t  f;
         int             first;
         int             size;
 
-        ASSERT(dir);
         ASSERT(fields);
-
         if (!fields)
                 return;
 
-        buf_ptr = (xfs_caddr_t)data;
-        mem_ptr = (xfs_caddr_t)sb;
-
         while (fields) {
                 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
                 first = xfs_sb_info[f].offset;
@@ -446,26 +488,20 @@ xfs_xlatesb(
                 ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
 
                 if (size == 1 || xfs_sb_info[f].type == 1) {
-                        if (dir > 0) {
-                                memcpy(mem_ptr + first, buf_ptr + first, size);
-                        } else {
-                                memcpy(buf_ptr + first, mem_ptr + first, size);
-                        }
+                        memcpy(to_ptr + first, from_ptr + first, size);
                 } else {
                         switch (size) {
                         case 2:
-                                INT_XLATE(*(__uint16_t*)(buf_ptr+first),
-                                          *(__uint16_t*)(mem_ptr+first),
-                                          dir, ARCH_CONVERT);
+                                *(__be16 *)(to_ptr + first) =
+                                        cpu_to_be16(*(__u16 *)(from_ptr + first));
                                 break;
                         case 4:
-                                INT_XLATE(*(__uint32_t*)(buf_ptr+first),
-                                          *(__uint32_t*)(mem_ptr+first),
-                                          dir, ARCH_CONVERT);
+                                *(__be32 *)(to_ptr + first) =
+                                        cpu_to_be32(*(__u32 *)(from_ptr + first));
                                 break;
                         case 8:
-                                INT_XLATE(*(__uint64_t*)(buf_ptr+first),
-                                          *(__uint64_t*)(mem_ptr+first), dir, ARCH_CONVERT);
+                                *(__be64 *)(to_ptr + first) =
+                                        cpu_to_be64(*(__u64 *)(from_ptr + first));
                                 break;
                         default:
                                 ASSERT(0);
@@ -487,7 +523,6 @@ xfs_readsb(xfs_mount_t *mp, int flags)
         unsigned int    sector_size;
         unsigned int    extra_flags;
         xfs_buf_t       *bp;
-        xfs_sb_t        *sbp;
         int             error;
 
         ASSERT(mp->m_sb_bp == NULL);
@@ -515,8 +550,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
          * Initialize the mount structure from the superblock.
          * But first do some basic consistency checking.
          */
-        sbp = XFS_BUF_TO_SBP(bp);
-        xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), 1, XFS_SB_ALL_BITS);
+        xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
 
         error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
         if (error) {
@@ -1335,11 +1369,28 @@ xfs_log_sbcount(
         return 0;
 }
 
+STATIC void
+xfs_mark_shared_ro(
+        xfs_mount_t     *mp,
+        xfs_buf_t       *bp)
+{
+        xfs_dsb_t       *sb = XFS_BUF_TO_SBP(bp);
+        __uint16_t      version;
+
+        if (!(sb->sb_flags & XFS_SBF_READONLY))
+                sb->sb_flags |= XFS_SBF_READONLY;
+
+        version = be16_to_cpu(sb->sb_versionnum);
+        if ((version & XFS_SB_VERSION_NUMBITS) != XFS_SB_VERSION_4 ||
+            !(version & XFS_SB_VERSION_SHAREDBIT))
+                version |= XFS_SB_VERSION_SHAREDBIT;
+        sb->sb_versionnum = cpu_to_be16(version);
+}
+
 int
 xfs_unmountfs_writesb(xfs_mount_t *mp)
 {
         xfs_buf_t       *sbp;
-        xfs_sb_t        *sb;
         int             error = 0;
 
         /*
@@ -1350,19 +1401,12 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
                 XFS_FORCED_SHUTDOWN(mp))) {
 
                 sbp = xfs_getsb(mp, 0);
-                sb = XFS_BUF_TO_SBP(sbp);
 
                 /*
                  * mark shared-readonly if desired
                  */
-                if (mp->m_mk_sharedro) {
-                        if (!(sb->sb_flags & XFS_SBF_READONLY))
-                                sb->sb_flags |= XFS_SBF_READONLY;
-                        if (!XFS_SB_VERSION_HASSHARED(sb))
-                                XFS_SB_VERSION_ADDSHARED(sb);
-                        xfs_fs_cmn_err(CE_NOTE, mp,
-                                "Unmounting, marking shared read-only");
-                }
+                if (mp->m_mk_sharedro)
+                        xfs_mark_shared_ro(mp, sbp);
 
                 XFS_BUF_UNDONE(sbp);
                 XFS_BUF_UNREAD(sbp);
@@ -1397,7 +1441,6 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
         int             first;
         int             last;
         xfs_mount_t     *mp;
-        xfs_sb_t        *sbp;
         xfs_sb_field_t  f;
 
         ASSERT(fields);
@@ -1405,13 +1448,12 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
                 return;
         mp = tp->t_mountp;
         bp = xfs_trans_getsb(tp, mp, 0);
-        sbp = XFS_BUF_TO_SBP(bp);
         first = sizeof(xfs_sb_t);
         last = 0;
 
         /* translate/copy */
 
-        xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), -1, fields);
+        xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
 
         /* find modified range */