xfs: return inode fork offset in bulkstat for fsr

So that fsr can attempt to get the fork offset of the temporary
inode it uses the same as the inode it is defragmenting, pass the
fork offset out in the bulkstat information.

The bulkstat structure has padding that has always been zeroed, so
userspace can tell if this field is set or not by use of the xattr
present flag and a non-zero value for the fork offset.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

2 files changed, 4 insertions, 1 deletions

diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index f52ac276277e..7cf7220e7d5f 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -292,7 +292,8 @@ typedef struct xfs_bstat {
         __s32           bs_extents;     /* number of extents            */
         __u32           bs_gen;         /* generation count             */
         __u16           bs_projid;      /* project id                   */
-        unsigned char   bs_pad[14];     /* pad space, unused            */
+        __u16           bs_forkoff;     /* inode fork offset in bytes   */
+        unsigned char   bs_pad[12];     /* pad space, unused            */
         __u32           bs_dmevmask;    /* DMIG event mask              */
         __u16           bs_dmstate;     /* DMIG state info              */
         __u16           bs_aextents;    /* attribute number of extents  */
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 3af02314c605..b1b801e4a28e 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -106,6 +106,7 @@ xfs_bulkstat_one_iget(
         buf->bs_dmevmask = dic->di_dmevmask;
         buf->bs_dmstate = dic->di_dmstate;
         buf->bs_aextents = dic->di_anextents;
+        buf->bs_forkoff = XFS_IFORK_BOFF(ip);
 
         switch (dic->di_format) {
         case XFS_DINODE_FMT_DEV:
@@ -176,6 +177,7 @@ xfs_bulkstat_one_dinode(
         buf->bs_dmevmask = be32_to_cpu(dic->di_dmevmask);
         buf->bs_dmstate = be16_to_cpu(dic->di_dmstate);
         buf->bs_aextents = be16_to_cpu(dic->di_anextents);
+        buf->bs_forkoff = XFS_DFORK_BOFF(dic);
 
         switch (dic->di_format) {
         case XFS_DINODE_FMT_DEV: