From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
xfs/347 occasionally deadlocks while running. Analysis of the D state
processes shows that there are a large number of workqueue threads all
trying to reserve transaction space to call xfs_reflink_end_cow_extent
and a single workqueue thread stuck in the same function trying to add
space as part of a regrant because we underestimate the number of times
that the remap operation needs to roll. That rolling thread is stuck
because all the other threads are ahead of it in line waiting for space.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_trans_resv.c | 7 +++++++
fs/xfs/libxfs/xfs_trans_resv.h | 2 ++
fs/xfs/xfs_reflink.c | 2 +-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index 477c67f1faa7..06e213ae1bd6 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -851,6 +851,13 @@ xfs_trans_resv_calc(
resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_write.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+ resp->tr_remap.tr_logres = xfs_calc_write_reservation(mp);
+ if (xfs_sb_version_hasreflink(&mp->m_sb))
+ resp->tr_remap.tr_logcount = XFS_REMAP_LOG_COUNT_REFLINK;
+ else
+ resp->tr_remap.tr_logcount = 0;
+ resp->tr_remap.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+
resp->tr_itruncate.tr_logres = xfs_calc_itruncate_reservation(mp);
if (xfs_sb_version_hasreflink(&mp->m_sb))
resp->tr_itruncate.tr_logcount =
diff --git a/fs/xfs/libxfs/xfs_trans_resv.h b/fs/xfs/libxfs/xfs_trans_resv.h
index 7f7d86671319..a685654adf21 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.h
+++ b/fs/xfs/libxfs/xfs_trans_resv.h
@@ -20,6 +20,7 @@ struct xfs_trans_res {
struct xfs_trans_resv {
struct xfs_trans_res tr_write; /* extent alloc trans */
+ struct xfs_trans_res tr_remap; /* extent remap trans */
struct xfs_trans_res tr_itruncate; /* truncate trans */
struct xfs_trans_res tr_rename; /* rename trans */
struct xfs_trans_res tr_link; /* link trans */
@@ -88,6 +89,7 @@ struct xfs_trans_resv {
#define XFS_RENAME_LOG_COUNT 2
#define XFS_WRITE_LOG_COUNT 2
#define XFS_WRITE_LOG_COUNT_REFLINK 8
+#define XFS_REMAP_LOG_COUNT_REFLINK 10
#define XFS_ADDAFORK_LOG_COUNT 2
#define XFS_ATTRINVAL_LOG_COUNT 1
#define XFS_ATTRSET_LOG_COUNT 3
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 680ae7662a78..6c84956ea833 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -630,7 +630,7 @@ xfs_reflink_end_cow_extent(
}
resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0,
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_remap, resblks, 0,
XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp);
if (error)
return error;
