xfs: use a union for i_cowextsize and i_flushiter

The i_cowextsize field is only used for v3 inodes, and the i_flushiter
field is only used for v1/v2 inodes.  Use a union to pack the inode a
littler better after adding a few missing guards around their usage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 3c7eb01c66ace4be3df0e1c5da510d1e0c3720ad..88ec7be551a89d68d1ce0040aa6e36008fe58e36 100644 (file)
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -193,7 +193,8 @@ xfs_inode_from_disk(
         * inode. If the inode is unused, mode is zero and we shouldn't mess
         * with the uninitialized part of it.
         */
-       ip->i_flushiter = be16_to_cpu(from->di_flushiter);
+       if (!xfs_sb_version_has_v3inode(&ip->i_mount->m_sb))
+               ip->i_flushiter = be16_to_cpu(from->di_flushiter);
        inode->i_generation = be32_to_cpu(from->di_gen);
        inode->i_mode = be16_to_cpu(from->di_mode);
        if (!inode->i_mode)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 06d779c9334b808f8643035c68ac2c6bf84c7ab7..e483c380afd1dbff09d751dc72af5f2b4717033c 100644 (file)
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3483,8 +3483,10 @@ xfs_iflush(
        xfs_inode_to_disk(ip, dip, iip->ili_item.li_lsn);
 
        /* Wrap, we never let the log put out DI_MAX_FLUSH */
-       if (ip->i_flushiter == DI_MAX_FLUSH)
-               ip->i_flushiter = 0;
+       if (!xfs_sb_version_has_v3inode(&mp->m_sb)) {
+               if (ip->i_flushiter == DI_MAX_FLUSH)
+                       ip->i_flushiter = 0;
+       }
 
        xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
        if (XFS_IFORK_Q(ip))

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index a76ca913f7698ce88e1a4367bcc98f1933e153fb..7a877db8ac568f411959bc02f16cfc83ca87826d 100644 (file)
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -58,8 +58,11 @@ typedef struct xfs_inode {
        xfs_rfsblock_t          i_nblocks;      /* # of direct & btree blocks */
        prid_t                  i_projid;       /* owner's project id */
        xfs_extlen_t            i_extsize;      /* basic/minimum extent size */
-       xfs_extlen_t            i_cowextsize;   /* basic cow extent size */
-       uint16_t                i_flushiter;    /* incremented on flush */
+       /* cowextsize is only used for v3 inodes, flushiter for v1/2 */
+       union {
+               xfs_extlen_t    i_cowextsize;   /* basic cow extent size */
+               uint16_t        i_flushiter;    /* incremented on flush */
+       };
 
        struct xfs_icdinode     i_d;            /* most of ondisk inode */
 

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 7909e46b5c5a18d93956ee6d7003885ea775d112..2028a4aa2bb20ad3443f3447103c0383efdb1e44 100644 (file)
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1123,7 +1123,8 @@ xfs_fill_fsxattr(
        simple_fill_fsxattr(fa, xfs_ip2xflags(ip));
 
        fa->fsx_extsize = XFS_FSB_TO_B(mp, ip->i_extsize);
-       fa->fsx_cowextsize = XFS_FSB_TO_B(mp, ip->i_cowextsize);
+       if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
+               fa->fsx_cowextsize = XFS_FSB_TO_B(mp, ip->i_cowextsize);
        fa->fsx_projid = ip->i_projid;
        if (ifp && (ifp->if_flags & XFS_IFEXTENTS))
                fa->fsx_nextents = xfs_iext_count(ifp);
@@ -1523,11 +1524,13 @@ xfs_ioctl_setattr(
                ip->i_extsize = XFS_B_TO_FSB(mp, fa->fsx_extsize);
        else
                ip->i_extsize = 0;
-       if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
-           (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE))
-               ip->i_cowextsize = XFS_B_TO_FSB(mp, fa->fsx_cowextsize);
-       else
-               ip->i_cowextsize = 0;
+
+       if (xfs_sb_version_has_v3inode(&mp->m_sb)) {
+               if (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)
+                       ip->i_cowextsize = XFS_B_TO_FSB(mp, fa->fsx_cowextsize);
+               else
+                       ip->i_cowextsize = 0;
+       }
 
        error = xfs_trans_commit(tp);