[PATCH 10/15] xfs: Introduce a new transaction for shrinking fs data section

[Jeff Liu <jeff.liu@xxxxxxxxxx>]

This is a new transaction which would be used for shrinking fs data section.

Signed-off-by: Jie Liu <jeff.liu@xxxxxxxxxx>
---
 fs/xfs/xfs_mount.h       |    1 +
 fs/xfs/xfs_trans.c       |   16 ++++++++++++++++
 fs/xfs/xfs_trans.h       |    7 +++++--
 fs/xfs/xfs_trans_space.h |    2 ++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 9eaea5a..9bf3ed6 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -41,6 +41,7 @@ typedef struct xfs_trans_reservations {
        uint    tr_growrtzero;  /* grow realtime zeroing */
        uint    tr_growrtfree;  /* grow realtime freeing */
        uint    tr_setagstate;  /* set a.g. state trans */
+       uint    tr_shrinkdata;  /* fs data section shrink trans */
 } xfs_trans_reservations_t;
 
 #ifndef __KERNEL__
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 5a5c4d8..d7346da 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -542,6 +542,21 @@ xfs_calc_set_agstate_reservation(
 }
 
 /*
+ * Shrinking the data section of the filesystem.
+ *     superblock
+ *     agi and agf
+ *     allocation btrees
+ */
+STATIC uint
+xfs_calc_shrinkdata_reservation(
+       struct xfs_mount        *mp)
+{
+       return mp->m_sb.sb_sectsize * 3 +
+               XFS_ALLOCFREE_LOG_RES(mp, 1) +
+               128 * (3 + XFS_ALLOCFREE_LOG_COUNT(mp, 1));
+}
+
+/*
  * Initialize the precomputed transaction reservation values
  * in the mount structure.
  */
@@ -573,6 +588,7 @@ xfs_trans_init(
        resp->tr_growrtzero = xfs_calc_growrtzero_reservation(mp);
        resp->tr_growrtfree = xfs_calc_growrtfree_reservation(mp);
        resp->tr_setagstate = xfs_calc_set_agstate_reservation(mp);
+       resp->tr_shrinkdata = xfs_calc_shrinkdata_reservation(mp);
 }
 
 /*
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 33aafda..6dc1fe8 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -109,7 +109,8 @@ typedef struct xfs_trans_header {
 #define        XFS_TRANS_CHECKPOINT            42
 #define XFS_TRANS_SET_AGSTATE          43
 #define XFS_TRANS_SWAPINO              44
-#define        XFS_TRANS_TYPE_MAX              44
+#define XFS_TRANS_SHRINKFS             45
+#define        XFS_TRANS_TYPE_MAX              45
 /* new transaction types need to be reflected in xfs_logprint(8) */
 
 #define XFS_TRANS_TYPES \
@@ -156,7 +157,8 @@ typedef struct xfs_trans_header {
        { XFS_TRANS_DUMMY2,             "DUMMY2" }, \
        { XLOG_UNMOUNT_REC_TYPE,        "UNMOUNT" }, \
        { XFS_TRANS_SET_AGSTATE,        "SET_AGSTATE" }, \
-       { XFS_TRANS_SWAPINO,            "SWAPINO" }
+       { XFS_TRANS_SWAPINO,            "SWAPINO" }, \
+       { XFS_TRANS_SHRINKFS,           "SHRINKFS" }
 
 /*
  * This structure is used to track log items associated with
@@ -267,6 +269,7 @@ struct xfs_log_item_desc {
 #define        XFS_ATTRRM_LOG_RES(mp)  ((mp)->m_reservations.tr_attrrm)
 #define        XFS_CLEAR_AGI_BUCKET_LOG_RES(mp)  
((mp)->m_reservations.tr_clearagi)
 #define XFS_SETAGSTATE_LOG_RES(mp) ((mp)->m_reservations.tr_setagstate)
+#define XFS_SHRINKDATA_LOG_RES(mp) ((mp)->m_reservations.tr_shrinkdata)
 
 /*
  * Various log count values.
diff --git a/fs/xfs/xfs_trans_space.h b/fs/xfs/xfs_trans_space.h
index 7d2c920..103e442 100644
--- a/fs/xfs/xfs_trans_space.h
+++ b/fs/xfs/xfs_trans_space.h
@@ -82,5 +82,7 @@
        (XFS_DIRREMOVE_SPACE_RES(mp) + XFS_DIRENTER_SPACE_RES(mp,nl))
 #define        XFS_SYMLINK_SPACE_RES(mp,nl,b)  \
        (XFS_IALLOC_SPACE_RES(mp) + XFS_DIRENTER_SPACE_RES(mp,nl) + (b))
+#define        XFS_SHRINKFS_SPACE_RES(mp)      \
+       (2 * XFS_AG_MAXLEVELS(mp))
 
 #endif /* __XFS_TRANS_SPACE_H__ */
-- 
1.7.4.1