From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Currently, block reservations in userspace transactions are not carried
over across transaction rolls. This will lead to ENOSPC failures inside
libxfs code which checks for reservation overruns in an upcoming patch
that borrows the bmbt repair code from the kernel because it makes
extensive use of transaction rolling.
Therefore, port t_blk_res_used from the kernel so that block
reservations work the same way in userspace.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
include/xfs_trans.h | 1 +
libxfs/trans.c | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/include/xfs_trans.h b/include/xfs_trans.h
index 54546da8..d0fc2a84 100644
--- a/include/xfs_trans.h
+++ b/include/xfs_trans.h
@@ -71,6 +71,7 @@ typedef struct xfs_trans {
unsigned int t_blk_res; /* # of blocks resvd */
xfs_fsblock_t t_firstblock; /* first block allocated */
struct xfs_mount *t_mountp; /* ptr to fs mount struct */
+ unsigned int t_blk_res_used; /* # of resvd blocks used */
unsigned int t_flags; /* misc flags */
long t_icount_delta; /* superblock icount change */
long t_ifree_delta; /* superblock ifree change */
diff --git a/libxfs/trans.c b/libxfs/trans.c
index 11a2098d..5ebca844 100644
--- a/libxfs/trans.c
+++ b/libxfs/trans.c
@@ -158,6 +158,9 @@ xfs_trans_dup(
/* We gave our writer reference to the new transaction */
tp->t_flags |= XFS_TRANS_NO_WRITECOUNT;
+ ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
+ tp->t_blk_res = tp->t_blk_res_used;
+
/* move deferred ops over to the new tp */
xfs_defer_move(ntp, tp);
@@ -775,6 +778,15 @@ libxfs_trans_mod_sb(
case XFS_TRANS_SB_RES_FDBLOCKS:
return;
case XFS_TRANS_SB_FDBLOCKS:
+ if (delta < 0) {
+ tp->t_blk_res_used += (uint)-delta;
+ if (tp->t_blk_res_used > tp->t_blk_res) {
+ fprintf(stderr,
+_("Transaction block reservation exceeded! %u > %u\n"),
+ tp->t_blk_res_used, tp->t_blk_res);
+ ASSERT(0);
+ }
+ }
tp->t_fdblocks_delta += delta;
break;
case XFS_TRANS_SB_ICOUNT:
