1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2013 Jie Liu.
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_mount.h"
13 #include "xfs_da_format.h"
14 #include "xfs_trans_space.h"
15 #include "xfs_da_btree.h"
16 #include "xfs_bmap_btree.h"
17 #include "xfs_trace.h"
20 * Calculate the maximum length in bytes that would be required for a local
21 * attribute value as large attributes out of line are not logged.
24 xfs_log_calc_max_attrsetm_res(
30 size = xfs_attr_leaf_entsize_local_max(mp->m_attr_geo->blksize) -
32 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
33 nblks += XFS_B_TO_FSB(mp, size);
34 nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);
36 return M_RES(mp)->tr_attrsetm.tr_logres +
37 M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
41 * Compute an alternate set of log reservation sizes for use exclusively with
42 * minimum log size calculations.
45 xfs_log_calc_trans_resv_for_minlogblocks(
47 struct xfs_trans_resv *resv)
49 unsigned int rmap_maxlevels = mp->m_rmap_maxlevels;
52 * In the early days of rmap+reflink, we always set the rmap maxlevels
53 * to 9 even if the AG was small enough that it would never grow to
54 * that height. Transaction reservation sizes influence the minimum
55 * log size calculation, which influences the size of the log that mkfs
56 * creates. Use the old value here to ensure that newly formatted
57 * small filesystems will mount on older kernels.
59 if (xfs_has_rmapbt(mp) && xfs_has_reflink(mp))
60 mp->m_rmap_maxlevels = XFS_OLD_REFLINK_RMAP_MAXLEVELS;
62 xfs_trans_resv_calc(mp, resv);
64 if (xfs_has_reflink(mp)) {
66 * In the early days of reflink, typical log operation counts
67 * were greatly overestimated.
69 resv->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
70 resv->tr_itruncate.tr_logcount =
71 XFS_ITRUNCATE_LOG_COUNT_REFLINK;
72 resv->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT_REFLINK;
73 } else if (xfs_has_rmapbt(mp)) {
75 * In the early days of non-reflink rmap, the impact of rmapbt
76 * updates on log counts were not taken into account at all.
78 resv->tr_write.tr_logcount = XFS_WRITE_LOG_COUNT;
79 resv->tr_itruncate.tr_logcount = XFS_ITRUNCATE_LOG_COUNT;
80 resv->tr_qm_dqalloc.tr_logcount = XFS_WRITE_LOG_COUNT;
83 /* Put everything back the way it was. This goes at the end. */
84 mp->m_rmap_maxlevels = rmap_maxlevels;
88 * Iterate over the log space reservation table to figure out and return
89 * the maximum one in terms of the pre-calculated values which were done
93 xfs_log_get_max_trans_res(
95 struct xfs_trans_res *max_resp)
97 struct xfs_trans_resv resv = {};
98 struct xfs_trans_res *resp;
99 struct xfs_trans_res *end_resp;
104 attr_space = xfs_log_calc_max_attrsetm_res(mp);
106 xfs_log_calc_trans_resv_for_minlogblocks(mp, &resv);
108 resp = (struct xfs_trans_res *)&resv;
109 end_resp = (struct xfs_trans_res *)(&resv + 1);
110 for (i = 0; resp < end_resp; i++, resp++) {
111 int tmp = resp->tr_logcount > 1 ?
112 resp->tr_logres * resp->tr_logcount :
115 trace_xfs_trans_resv_calc_minlogsize(mp, i, resp);
116 if (log_space < tmp) {
118 *max_resp = *resp; /* struct copy */
122 if (attr_space > log_space) {
123 *max_resp = resv.tr_attrsetm; /* struct copy */
124 max_resp->tr_logres = attr_space;
126 trace_xfs_log_get_max_trans_res(mp, max_resp);
130 * Calculate the minimum valid log size for the given superblock configuration.
131 * Used to calculate the minimum log size at mkfs time, and to determine if
132 * the log is large enough or not at mount time. Returns the minimum size in
133 * filesystem block size units.
136 xfs_log_calc_minimum_size(
137 struct xfs_mount *mp)
139 struct xfs_trans_res tres = {0};
144 xfs_log_get_max_trans_res(mp, &tres);
146 max_logres = xfs_log_calc_unit_res(mp, tres.tr_logres);
147 if (tres.tr_logcount > 1)
148 max_logres *= tres.tr_logcount;
150 if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1)
151 lsunit = BTOBB(mp->m_sb.sb_logsunit);
154 * Two factors should be taken into account for calculating the minimum
156 * 1) The fundamental limitation is that no single transaction can be
157 * larger than half size of the log.
159 * From mkfs.xfs, this is considered by the XFS_MIN_LOG_FACTOR
160 * define, which is set to 3. That means we can definitely fit
161 * maximally sized 2 transactions in the log. We'll use this same
164 * 2) If the lsunit option is specified, a transaction requires 2 LSU
165 * for the reservation because there are two log writes that can
166 * require padding - the transaction data and the commit record which
167 * are written separately and both can require padding to the LSU.
168 * Consider that we can have an active CIL reservation holding 2*LSU,
169 * but the CIL is not over a push threshold, in this case, if we
170 * don't have enough log space for at one new transaction, which
171 * includes another 2*LSU in the reservation, we will run into dead
172 * loop situation in log space grant procedure. i.e.
173 * xlog_grant_head_wait().
175 * Hence the log size needs to be able to contain two maximally sized
176 * and padded transactions, which is (2 * (2 * LSU + maxlres)).
178 * Also, the log size should be a multiple of the log stripe unit, round
179 * it up to lsunit boundary if lsunit is specified.
182 min_logblks = roundup_64(BTOBB(max_logres), lsunit) +
185 min_logblks = BTOBB(max_logres) + 2 * BBSIZE;
186 min_logblks *= XFS_MIN_LOG_FACTOR;
188 return XFS_BB_TO_FSB(mp, min_logblks);