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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/sched.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <linux/completion.h>
16#include <linux/buffer_head.h>
17#include <linux/kallsyms.h>
18#include <linux/gfs2_ondisk.h>
19
20#include "gfs2.h"
21#include "incore.h"
22#include "glock.h"
23#include "inode.h"
24#include "log.h"
25#include "lops.h"
26#include "meta_io.h"
27#include "trans.h"
28#include "util.h"
29#include "trace_gfs2.h"
30
31int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
32		     unsigned int revokes)
33{
34	struct gfs2_trans *tr;
35	int error;
36
37	BUG_ON(current->journal_info);
38	BUG_ON(blocks == 0 && revokes == 0);
39
40	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
41		return -EROFS;
42
43	tr = kzalloc(sizeof(struct gfs2_trans), GFP_NOFS);
44	if (!tr)
45		return -ENOMEM;
46
47	tr->tr_ip = _RET_IP_;
48	tr->tr_blocks = blocks;
49	tr->tr_revokes = revokes;
50	tr->tr_reserved = 1;
51	tr->tr_alloced = 1;
52	if (blocks)
53		tr->tr_reserved += 6 + blocks;
54	if (revokes)
55		tr->tr_reserved += gfs2_struct2blk(sdp, revokes,
56						   sizeof(u64));
57	INIT_LIST_HEAD(&tr->tr_databuf);
58	INIT_LIST_HEAD(&tr->tr_buf);
59
60	sb_start_intwrite(sdp->sd_vfs);
61
62	error = gfs2_log_reserve(sdp, tr->tr_reserved);
63	if (error)
64		goto fail;
65
66	current->journal_info = tr;
67
68	return 0;
69
70fail:
71	sb_end_intwrite(sdp->sd_vfs);
72	kfree(tr);
73
74	return error;
75}
76
77static void gfs2_print_trans(const struct gfs2_trans *tr)
78{
79	pr_warn("Transaction created at: %pSR\n", (void *)tr->tr_ip);
80	pr_warn("blocks=%u revokes=%u reserved=%u touched=%u\n",
81		tr->tr_blocks, tr->tr_revokes, tr->tr_reserved, tr->tr_touched);
82	pr_warn("Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
83		tr->tr_num_buf_new, tr->tr_num_buf_rm,
84		tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
85		tr->tr_num_revoke, tr->tr_num_revoke_rm);
86}
87
88void gfs2_trans_end(struct gfs2_sbd *sdp)
89{
90	struct gfs2_trans *tr = current->journal_info;
91	s64 nbuf;
92	BUG_ON(!tr);
93	current->journal_info = NULL;
94
95	if (!tr->tr_touched) {
96		gfs2_log_release(sdp, tr->tr_reserved);
97		if (tr->tr_alloced)
98			kfree(tr);
99		sb_end_intwrite(sdp->sd_vfs);
100		return;
101	}
102
103	nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
104	nbuf -= tr->tr_num_buf_rm;
105	nbuf -= tr->tr_num_databuf_rm;
106
107	if (gfs2_assert_withdraw(sdp, (nbuf <= tr->tr_blocks) &&
108				       (tr->tr_num_revoke <= tr->tr_revokes)))
109		gfs2_print_trans(tr);
110
111	gfs2_log_commit(sdp, tr);
112	if (tr->tr_alloced && !tr->tr_attached)
113			kfree(tr);
114	up_read(&sdp->sd_log_flush_lock);
115
116	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
117		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
118	sb_end_intwrite(sdp->sd_vfs);
119}
120
121static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
122					       struct buffer_head *bh,
123					       const struct gfs2_log_operations *lops)
124{
125	struct gfs2_bufdata *bd;
126
127	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
128	bd->bd_bh = bh;
129	bd->bd_gl = gl;
130	bd->bd_ops = lops;
131	INIT_LIST_HEAD(&bd->bd_list);
132	bh->b_private = bd;
133	return bd;
134}
135
136/**
137 * gfs2_trans_add_data - Add a databuf to the transaction.
138 * @gl: The inode glock associated with the buffer
139 * @bh: The buffer to add
140 *
141 * This is used in two distinct cases:
142 * i) In ordered write mode
143 *    We put the data buffer on a list so that we can ensure that its
144 *    synced to disk at the right time
145 * ii) In journaled data mode
146 *    We need to journal the data block in the same way as metadata in
147 *    the functions above. The difference is that here we have a tag
148 *    which is two __be64's being the block number (as per meta data)
149 *    and a flag which says whether the data block needs escaping or
150 *    not. This means we need a new log entry for each 251 or so data
151 *    blocks, which isn't an enormous overhead but twice as much as
152 *    for normal metadata blocks.
153 */
154void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
155{
156	struct gfs2_trans *tr = current->journal_info;
157	struct gfs2_sbd *sdp = gl->gl_sbd;
158	struct address_space *mapping = bh->b_page->mapping;
159	struct gfs2_inode *ip = GFS2_I(mapping->host);
160	struct gfs2_bufdata *bd;
161
162	if (!gfs2_is_jdata(ip)) {
163		gfs2_ordered_add_inode(ip);
164		return;
165	}
166
167	lock_buffer(bh);
168	gfs2_log_lock(sdp);
169	bd = bh->b_private;
170	if (bd == NULL) {
171		gfs2_log_unlock(sdp);
172		unlock_buffer(bh);
173		if (bh->b_private == NULL)
174			bd = gfs2_alloc_bufdata(gl, bh, &gfs2_databuf_lops);
175		lock_buffer(bh);
176		gfs2_log_lock(sdp);
177	}
178	gfs2_assert(sdp, bd->bd_gl == gl);
179	tr->tr_touched = 1;
180	if (list_empty(&bd->bd_list)) {
181		set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
182		set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
183		gfs2_pin(sdp, bd->bd_bh);
184		tr->tr_num_databuf_new++;
185		list_add_tail(&bd->bd_list, &tr->tr_databuf);
186	}
187	gfs2_log_unlock(sdp);
188	unlock_buffer(bh);
189}
190
191static void meta_lo_add(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
192{
193	struct gfs2_meta_header *mh;
194	struct gfs2_trans *tr;
195
196	tr = current->journal_info;
197	tr->tr_touched = 1;
198	if (!list_empty(&bd->bd_list))
199		return;
200	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
201	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
202	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
203	if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {
204		pr_err("Attempting to add uninitialised block to journal (inplace block=%lld)\n",
205		       (unsigned long long)bd->bd_bh->b_blocknr);
206		BUG();
207	}
208	gfs2_pin(sdp, bd->bd_bh);
209	mh->__pad0 = cpu_to_be64(0);
210	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
211	list_add(&bd->bd_list, &tr->tr_buf);
212	tr->tr_num_buf_new++;
213}
214
215void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
216{
217
218	struct gfs2_sbd *sdp = gl->gl_sbd;
219	struct gfs2_bufdata *bd;
220
221	lock_buffer(bh);
222	gfs2_log_lock(sdp);
223	bd = bh->b_private;
224	if (bd == NULL) {
225		gfs2_log_unlock(sdp);
226		unlock_buffer(bh);
227		lock_page(bh->b_page);
228		if (bh->b_private == NULL)
229			bd = gfs2_alloc_bufdata(gl, bh, &gfs2_buf_lops);
230		unlock_page(bh->b_page);
231		lock_buffer(bh);
232		gfs2_log_lock(sdp);
233	}
234	gfs2_assert(sdp, bd->bd_gl == gl);
235	meta_lo_add(sdp, bd);
236	gfs2_log_unlock(sdp);
237	unlock_buffer(bh);
238}
239
240void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
241{
242	struct gfs2_trans *tr = current->journal_info;
243
244	BUG_ON(!list_empty(&bd->bd_list));
245	gfs2_add_revoke(sdp, bd);
246	tr->tr_touched = 1;
247	tr->tr_num_revoke++;
248}
249
250void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
251{
252	struct gfs2_bufdata *bd, *tmp;
253	struct gfs2_trans *tr = current->journal_info;
254	unsigned int n = len;
255
256	gfs2_log_lock(sdp);
257	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_list) {
258		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
259			list_del_init(&bd->bd_list);
260			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
261			sdp->sd_log_num_revoke--;
262			kmem_cache_free(gfs2_bufdata_cachep, bd);
263			tr->tr_num_revoke_rm++;
264			if (--n == 0)
265				break;
266		}
267	}
268	gfs2_log_unlock(sdp);
269}
270
271