[RFC PATCH 06/13] :xfs: extent transaction reservations for parent attributes

Allison Henderson
2017-08-10T01:43:52Z

From: Dave Chinner <dchinner@redhat.com>

We need to add, remove or modify parent pointer attributes during
create/link/unlink/rename operations atomically with the dirents in the parent
directories being modified. This means they need to be modified in the same
transaction as the parent directories, and so we need to add the required
space for the attribute modifications to the transaction reservations.

[achender: rebased, added xfs_sb_version_hasparent stub]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
:100644 100644 91e2d5a... 6cedd75... M fs/xfs/libxfs/xfs_format.h
:100644 100644 6bd916b... 54399e2... M fs/xfs/libxfs/xfs_trans_resv.c
fs/xfs/libxfs/xfs_format.h | 5 ++
fs/xfs/libxfs/xfs_trans_resv.c | 103 ++++++++++++++++++++++++++++++++---------
2 files changed, 85 insertions(+), 23 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 91e2d5a..6cedd75 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -561,6 +561,11 @@ static inline bool xfs_sb_version_hasreflink(struct xfs_sb *sbp)
(sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK);
}

+static inline bool xfs_sb_version_hasparent(struct xfs_sb *sbp)
+{
+ return false; /* We'll enable this at the end of the set */
+}
+
/*
* end of superblock version macros
*/
diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c
index 6bd916b..54399e2 100644
--- a/fs/xfs/libxfs/xfs_trans_resv.c
+++ b/fs/xfs/libxfs/xfs_trans_resv.c
@@ -802,29 +802,30 @@ xfs_calc_sb_reservation(
return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
}

+/*
+ * Namespace reservations.
+ *
+ * These get tricky when parent pointers are enabled as we have attribute
+ * modifications occurring from within these transactions. Rather than confuse
+ * each of these reservation calculations with the conditional attribute
+ * reservations, add them here in a clear and concise manner. This assumes that
+ * the attribute reservations have already been calculated.
+ *
+ * Note that we only include the static attribute reservation here; the runtime
+ * reservation will have to be modified by the size of the attributes being
+ * added/removed/modified. See the comments on the attribute reservation
+ * calculations for more details.
+ *
+ * Note for rename: rename will vastly overestimate requirements. This will be
+ * addressed later when modifications are made to ensure parent attribute
+ * modifications can be done atomically with the rename operation.
+ */
void
-xfs_trans_resv_calc(
+xfs_calc_namespace_reservations(
struct xfs_mount *mp,
struct xfs_trans_resv *resp)
{
- /*
- * The following transactions are logged in physical format and
- * require a permanent reservation on space.
- */
- resp->tr_write.tr_logres = xfs_calc_write_reservation(mp);
- if (xfs_sb_version_hasreflink(&mp->m_sb))
- resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
- else
- resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
- resp->tr_write.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 =
- XFS_ITRUNCATE_LOG_COUNT_REFLINK;
- else
- resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
- resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+ ASSERT(resp->tr_attrsetm.tr_logres > 0);

resp->tr_rename.tr_logres = xfs_calc_rename_reservation(mp);
resp->tr_rename.tr_logcount = XFS_RENAME_LOG_COUNT;
@@ -846,15 +847,69 @@ xfs_trans_resv_calc(
resp->tr_create.tr_logcount = XFS_CREATE_LOG_COUNT;
resp->tr_create.tr_logflags |= XFS_TRANS_PERM_LOG_RES;

+ resp->tr_mkdir.tr_logres = xfs_calc_mkdir_reservation(mp);
+ resp->tr_mkdir.tr_logcount = XFS_MKDIR_LOG_COUNT;
+ resp->tr_mkdir.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+
+ if (!xfs_sb_version_hasparent(&mp->m_sb))
+ return;
+
+ /* rename can add/remove/modify 2 parent attributes */
+ resp->tr_rename.tr_logres += 2 * max(resp->tr_attrsetm.tr_logres,
+ resp->tr_attrrm.tr_logres);
+ resp->tr_rename.tr_logcount += 2 * max(resp->tr_attrsetm.tr_logcount,
+ resp->tr_attrrm.tr_logcount);
+
+ /* create will add 1 parent attribute */
+ resp->tr_create.tr_logres += resp->tr_attrsetm.tr_logres;
+ resp->tr_create.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+ /* mkdir will add 1 parent attribute */
+ resp->tr_mkdir.tr_logres += resp->tr_attrsetm.tr_logres;
+ resp->tr_mkdir.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+ /* link will add 1 parent attribute */
+ resp->tr_link.tr_logres += resp->tr_attrsetm.tr_logres;
+ resp->tr_link.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+ /* symlink will add 1 parent attribute */
+ resp->tr_symlink.tr_logres += resp->tr_attrsetm.tr_logres;
+ resp->tr_symlink.tr_logcount += resp->tr_attrsetm.tr_logcount;
+
+ /* remove will remove 1 parent attribute */
+ resp->tr_remove.tr_logres += resp->tr_attrrm.tr_logres;
+ resp->tr_remove.tr_logcount = resp->tr_attrrm.tr_logcount;
+}
+
+void
+xfs_trans_resv_calc(
+ struct xfs_mount *mp,
+ struct xfs_trans_resv *resp)
+{
+ /*
+ * The following transactions are logged in physical format and
+ * require a permanent reservation on space.
+ */
+ resp->tr_write.tr_logres = xfs_calc_write_reservation(mp);
+ if (xfs_sb_version_hasreflink(&mp->m_sb))
+ resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
+ else
+ resp->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
+ resp->tr_write.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 =
+ XFS_ITRUNCATE_LOG_COUNT_REFLINK;
+ else
+ resp->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
+ resp->tr_itruncate.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
+
resp->tr_create_tmpfile.tr_logres =
xfs_calc_create_tmpfile_reservation(mp);
resp->tr_create_tmpfile.tr_logcount = XFS_CREATE_TMPFILE_LOG_COUNT;
resp->tr_create_tmpfile.tr_logflags |= XFS_TRANS_PERM_LOG_RES;

- resp->tr_mkdir.tr_logres = xfs_calc_mkdir_reservation(mp);
- resp->tr_mkdir.tr_logcount = XFS_MKDIR_LOG_COUNT;
- resp->tr_mkdir.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
-
resp->tr_ifree.tr_logres = xfs_calc_ifree_reservation(mp);
resp->tr_ifree.tr_logcount = XFS_INACTIVE_LOG_COUNT;
resp->tr_ifree.tr_logflags |= XFS_TRANS_PERM_LOG_RES;
@@ -886,6 +941,8 @@ xfs_trans_resv_calc(
resp->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
resp->tr_qm_dqalloc.tr_logflags |= XFS_TRANS_PERM_LOG_RES;

+ xfs_calc_namespace_reservations(mp, resp);
+
/*
* The following transactions are logged in logical format with
* a default log count.
--
2.7.4