KVM: PPC: Book3S: Fix compile error that occurs with some gcc versions
[linux/fpc-iii.git] / fs / xfs / libxfs / xfs_log_rlimit.c
blobcc4cbe290939255c2279052ae773bea227f42d70
1 /*
2 * Copyright (c) 2013 Jie Liu.
3 * All Rights Reserved.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_mount.h"
25 #include "xfs_da_format.h"
26 #include "xfs_trans_space.h"
27 #include "xfs_inode.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_attr_leaf.h"
30 #include "xfs_bmap_btree.h"
33 * Calculate the maximum length in bytes that would be required for a local
34 * attribute value as large attributes out of line are not logged.
36 STATIC int
37 xfs_log_calc_max_attrsetm_res(
38 struct xfs_mount *mp)
40 int size;
41 int nblks;
43 size = xfs_attr_leaf_entsize_local_max(mp->m_attr_geo->blksize) -
44 MAXNAMELEN - 1;
45 nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
46 nblks += XFS_B_TO_FSB(mp, size);
47 nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK);
49 return M_RES(mp)->tr_attrsetm.tr_logres +
50 M_RES(mp)->tr_attrsetrt.tr_logres * nblks;
54 * Iterate over the log space reservation table to figure out and return
55 * the maximum one in terms of the pre-calculated values which were done
56 * at mount time.
58 void
59 xfs_log_get_max_trans_res(
60 struct xfs_mount *mp,
61 struct xfs_trans_res *max_resp)
63 struct xfs_trans_res *resp;
64 struct xfs_trans_res *end_resp;
65 int log_space = 0;
66 int attr_space;
68 attr_space = xfs_log_calc_max_attrsetm_res(mp);
70 resp = (struct xfs_trans_res *)M_RES(mp);
71 end_resp = (struct xfs_trans_res *)(M_RES(mp) + 1);
72 for (; resp < end_resp; resp++) {
73 int tmp = resp->tr_logcount > 1 ?
74 resp->tr_logres * resp->tr_logcount :
75 resp->tr_logres;
76 if (log_space < tmp) {
77 log_space = tmp;
78 *max_resp = *resp; /* struct copy */
82 if (attr_space > log_space) {
83 *max_resp = M_RES(mp)->tr_attrsetm; /* struct copy */
84 max_resp->tr_logres = attr_space;
89 * Calculate the minimum valid log size for the given superblock configuration.
90 * Used to calculate the minimum log size at mkfs time, and to determine if
91 * the log is large enough or not at mount time. Returns the minimum size in
92 * filesystem block size units.
94 int
95 xfs_log_calc_minimum_size(
96 struct xfs_mount *mp)
98 struct xfs_trans_res tres = {0};
99 int max_logres;
100 int min_logblks = 0;
101 int lsunit = 0;
103 xfs_log_get_max_trans_res(mp, &tres);
105 max_logres = xfs_log_calc_unit_res(mp, tres.tr_logres);
106 if (tres.tr_logcount > 1)
107 max_logres *= tres.tr_logcount;
109 if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1)
110 lsunit = BTOBB(mp->m_sb.sb_logsunit);
113 * Two factors should be taken into account for calculating the minimum
114 * log space.
115 * 1) The fundamental limitation is that no single transaction can be
116 * larger than half size of the log.
118 * From mkfs.xfs, this is considered by the XFS_MIN_LOG_FACTOR
119 * define, which is set to 3. That means we can definitely fit
120 * maximally sized 2 transactions in the log. We'll use this same
121 * value here.
123 * 2) If the lsunit option is specified, a transaction requires 2 LSU
124 * for the reservation because there are two log writes that can
125 * require padding - the transaction data and the commit record which
126 * are written separately and both can require padding to the LSU.
127 * Consider that we can have an active CIL reservation holding 2*LSU,
128 * but the CIL is not over a push threshold, in this case, if we
129 * don't have enough log space for at one new transaction, which
130 * includes another 2*LSU in the reservation, we will run into dead
131 * loop situation in log space grant procedure. i.e.
132 * xlog_grant_head_wait().
134 * Hence the log size needs to be able to contain two maximally sized
135 * and padded transactions, which is (2 * (2 * LSU + maxlres)).
137 * Also, the log size should be a multiple of the log stripe unit, round
138 * it up to lsunit boundary if lsunit is specified.
140 if (lsunit) {
141 min_logblks = roundup_64(BTOBB(max_logres), lsunit) +
142 2 * lsunit;
143 } else
144 min_logblks = BTOBB(max_logres) + 2 * BBSIZE;
145 min_logblks *= XFS_MIN_LOG_FACTOR;
147 return XFS_BB_TO_FSB(mp, min_logblks);