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-rw-r--r--fs/xfs/libxfs/xfs_log_rlimit.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_log_rlimit.c b/fs/xfs/libxfs/xfs_log_rlimit.c
new file mode 100644
index 000000000..7f55eb3f3
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_log_rlimit.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2013 Jie Liu.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_trans_space.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+
+/*
+ * Calculate the maximum length in bytes that would be required for a local
+ * attribute value as large attributes out of line are not logged.
+ */
+STATIC int
+xfs_log_calc_max_attrsetm_res(
+ struct xfs_mount *mp)
+{
+ int size;
+ int nblks;
+
+ size = xfs_attr_leaf_entsize_local_max(mp->m_attr_geo->blksize) -
+ MAXNAMELEN - 1;
+ nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
+ nblks += XFS_B_TO_FSB(mp, size);
+ nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);
+
+ return M_RES(mp)->tr_attrsetm.tr_logres +
+ M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
+}
+
+/*
+ * Iterate over the log space reservation table to figure out and return
+ * the maximum one in terms of the pre-calculated values which were done
+ * at mount time.
+ */
+void
+xfs_log_get_max_trans_res(
+ struct xfs_mount *mp,
+ struct xfs_trans_res *max_resp)
+{
+ struct xfs_trans_res *resp;
+ struct xfs_trans_res *end_resp;
+ int log_space = 0;
+ int attr_space;
+
+ attr_space = xfs_log_calc_max_attrsetm_res(mp);
+
+ resp = (struct xfs_trans_res *)M_RES(mp);
+ end_resp = (struct xfs_trans_res *)(M_RES(mp) + 1);
+ for (; resp < end_resp; resp++) {
+ int tmp = resp->tr_logcount > 1 ?
+ resp->tr_logres * resp->tr_logcount :
+ resp->tr_logres;
+ if (log_space < tmp) {
+ log_space = tmp;
+ *max_resp = *resp; /* struct copy */
+ }
+ }
+
+ if (attr_space > log_space) {
+ *max_resp = M_RES(mp)->tr_attrsetm; /* struct copy */
+ max_resp->tr_logres = attr_space;
+ }
+}
+
+/*
+ * Calculate the minimum valid log size for the given superblock configuration.
+ * Used to calculate the minimum log size at mkfs time, and to determine if
+ * the log is large enough or not at mount time. Returns the minimum size in
+ * filesystem block size units.
+ */
+int
+xfs_log_calc_minimum_size(
+ struct xfs_mount *mp)
+{
+ struct xfs_trans_res tres = {0};
+ int max_logres;
+ int min_logblks = 0;
+ int lsunit = 0;
+
+ xfs_log_get_max_trans_res(mp, &tres);
+
+ max_logres = xfs_log_calc_unit_res(mp, tres.tr_logres);
+ if (tres.tr_logcount > 1)
+ max_logres *= tres.tr_logcount;
+
+ if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1)
+ lsunit = BTOBB(mp->m_sb.sb_logsunit);
+
+ /*
+ * Two factors should be taken into account for calculating the minimum
+ * log space.
+ * 1) The fundamental limitation is that no single transaction can be
+ * larger than half size of the log.
+ *
+ * From mkfs.xfs, this is considered by the XFS_MIN_LOG_FACTOR
+ * define, which is set to 3. That means we can definitely fit
+ * maximally sized 2 transactions in the log. We'll use this same
+ * value here.
+ *
+ * 2) If the lsunit option is specified, a transaction requires 2 LSU
+ * for the reservation because there are two log writes that can
+ * require padding - the transaction data and the commit record which
+ * are written separately and both can require padding to the LSU.
+ * Consider that we can have an active CIL reservation holding 2*LSU,
+ * but the CIL is not over a push threshold, in this case, if we
+ * don't have enough log space for at one new transaction, which
+ * includes another 2*LSU in the reservation, we will run into dead
+ * loop situation in log space grant procedure. i.e.
+ * xlog_grant_head_wait().
+ *
+ * Hence the log size needs to be able to contain two maximally sized
+ * and padded transactions, which is (2 * (2 * LSU + maxlres)).
+ *
+ * Also, the log size should be a multiple of the log stripe unit, round
+ * it up to lsunit boundary if lsunit is specified.
+ */
+ if (lsunit) {
+ min_logblks = roundup_64(BTOBB(max_logres), lsunit) +
+ 2 * lsunit;
+ } else
+ min_logblks = BTOBB(max_logres) + 2 * BBSIZE;
+ min_logblks *= XFS_MIN_LOG_FACTOR;
+
+ return XFS_BB_TO_FSB(mp, min_logblks);
+}