xref: /linux/fs/gfs2/trans.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/kallsyms.h>
16 #include <linux/gfs2_ondisk.h>
17 
18 #include "gfs2.h"
19 #include "incore.h"
20 #include "glock.h"
21 #include "log.h"
22 #include "lops.h"
23 #include "meta_io.h"
24 #include "trans.h"
25 #include "util.h"
26 #include "trace_gfs2.h"
27 
28 int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
29 		     unsigned int revokes)
30 {
31 	struct gfs2_trans *tr;
32 	int error;
33 
34 	BUG_ON(current->journal_info);
35 	BUG_ON(blocks == 0 && revokes == 0);
36 
37 	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
38 		return -EROFS;
39 
40 	tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
41 	if (!tr)
42 		return -ENOMEM;
43 
44 	tr->tr_ip = (unsigned long)__builtin_return_address(0);
45 	tr->tr_blocks = blocks;
46 	tr->tr_revokes = revokes;
47 	tr->tr_reserved = 1;
48 	if (blocks)
49 		tr->tr_reserved += 6 + blocks;
50 	if (revokes)
51 		tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
52 						   sizeof(u64));
53 	gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);
54 
55 	error = gfs2_glock_nq(&tr->tr_t_gh);
56 	if (error)
57 		goto fail_holder_uninit;
58 
59 	error = gfs2_log_reserve(sdp, tr->tr_reserved);
60 	if (error)
61 		goto fail_gunlock;
62 
63 	current->journal_info = tr;
64 
65 	return 0;
66 
67 fail_gunlock:
68 	gfs2_glock_dq(&tr->tr_t_gh);
69 
70 fail_holder_uninit:
71 	gfs2_holder_uninit(&tr->tr_t_gh);
72 	kfree(tr);
73 
74 	return error;
75 }
76 
77 /**
78  * gfs2_log_release - Release a given number of log blocks
79  * @sdp: The GFS2 superblock
80  * @blks: The number of blocks
81  *
82  */
83 
84 static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
85 {
86 
87 	atomic_add(blks, &sdp->sd_log_blks_free);
88 	trace_gfs2_log_blocks(sdp, blks);
89 	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
90 				  sdp->sd_jdesc->jd_blocks);
91 	up_read(&sdp->sd_log_flush_lock);
92 }
93 
94 static void gfs2_print_trans(const struct gfs2_trans *tr)
95 {
96 	print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
97 	printk(KERN_WARNING "GFS2: blocks=%u revokes=%u reserved=%u touched=%d\n",
98 	       tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
99 	printk(KERN_WARNING "GFS2: Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
100 	       tr->tr_num_buf_new, tr->tr_num_buf_rm,
101 	       tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
102 	       tr->tr_num_revoke, tr->tr_num_revoke_rm);
103 }
104 
105 void gfs2_trans_end(struct gfs2_sbd *sdp)
106 {
107 	struct gfs2_trans *tr = current->journal_info;
108 	s64 nbuf;
109 	BUG_ON(!tr);
110 	current->journal_info = NULL;
111 
112 	if (!tr->tr_touched) {
113 		gfs2_log_release(sdp, tr->tr_reserved);
114 		if (tr->tr_t_gh.gh_gl) {
115 			gfs2_glock_dq(&tr->tr_t_gh);
116 			gfs2_holder_uninit(&tr->tr_t_gh);
117 			kfree(tr);
118 		}
119 		return;
120 	}
121 
122 	nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
123 	nbuf -= tr->tr_num_buf_rm;
124 	nbuf -= tr->tr_num_databuf_rm;
125 
126 	if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
127 				       (tr->tr_num_revoke <= tr->tr_revokes)))
128 		gfs2_print_trans(tr);
129 
130 	gfs2_log_commit(sdp, tr);
131 	if (tr->tr_t_gh.gh_gl) {
132 		gfs2_glock_dq(&tr->tr_t_gh);
133 		gfs2_holder_uninit(&tr->tr_t_gh);
134 		kfree(tr);
135 	}
136 
137 	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
138 		gfs2_log_flush(sdp, NULL);
139 }
140 
141 /**
142  * gfs2_trans_add_bh - Add a to-be-modified buffer to the current transaction
143  * @gl: the glock the buffer belongs to
144  * @bh: The buffer to add
145  * @meta: True in the case of adding metadata
146  *
147  */
148 
149 void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
150 {
151 	struct gfs2_sbd *sdp = gl->gl_sbd;
152 	struct gfs2_bufdata *bd;
153 
154 	bd = bh->b_private;
155 	if (bd)
156 		gfs2_assert(sdp, bd->bd_gl == gl);
157 	else {
158 		gfs2_attach_bufdata(gl, bh, meta);
159 		bd = bh->b_private;
160 	}
161 	lops_add(sdp, bd);
162 }
163 
164 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
165 {
166 	BUG_ON(!list_empty(&bd->bd_list));
167 	BUG_ON(!list_empty(&bd->bd_ail_st_list));
168 	BUG_ON(!list_empty(&bd->bd_ail_gl_list));
169 	lops_init_le(bd, &gfs2_revoke_lops);
170 	lops_add(sdp, bd);
171 }
172 
173 void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
174 {
175 	struct gfs2_bufdata *bd, *tmp;
176 	struct gfs2_trans *tr = current->journal_info;
177 	unsigned int n = len;
178 
179 	gfs2_log_lock(sdp);
180 	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_list) {
181 		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
182 			list_del_init(&bd->bd_list);
183 			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
184 			sdp->sd_log_num_revoke--;
185 			kmem_cache_free(gfs2_bufdata_cachep, bd);
186 			tr->tr_num_revoke_rm++;
187 			if (--n == 0)
188 				break;
189 		}
190 	}
191 	gfs2_log_unlock(sdp);
192 }
193 
194