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 
gfs2_trans_begin(struct gfs2_sbd * sdp,unsigned int blocks,unsigned int revokes)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 	INIT_LIST_HEAD(&tr->tr_list_buf);
54 
55 	gfs2_holder_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &tr->tr_t_gh);
56 
57 	error = gfs2_glock_nq(&tr->tr_t_gh);
58 	if (error)
59 		goto fail_holder_uninit;
60 
61 	error = gfs2_log_reserve(sdp, tr->tr_reserved);
62 	if (error)
63 		goto fail_gunlock;
64 
65 	current->journal_info = tr;
66 
67 	return 0;
68 
69 fail_gunlock:
70 	gfs2_glock_dq(&tr->tr_t_gh);
71 
72 fail_holder_uninit:
73 	gfs2_holder_uninit(&tr->tr_t_gh);
74 	kfree(tr);
75 
76 	return error;
77 }
78 
79 /**
80  * gfs2_log_release - Release a given number of log blocks
81  * @sdp: The GFS2 superblock
82  * @blks: The number of blocks
83  *
84  */
85 
gfs2_log_release(struct gfs2_sbd * sdp,unsigned int blks)86 static void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
87 {
88 
89 	atomic_add(blks, &sdp->sd_log_blks_free);
90 	trace_gfs2_log_blocks(sdp, blks);
91 	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
92 				  sdp->sd_jdesc->jd_blocks);
93 	up_read(&sdp->sd_log_flush_lock);
94 }
95 
gfs2_trans_end(struct gfs2_sbd * sdp)96 void gfs2_trans_end(struct gfs2_sbd *sdp)
97 {
98 	struct gfs2_trans *tr = current->journal_info;
99 
100 	BUG_ON(!tr);
101 	current->journal_info = NULL;
102 
103 	if (!tr->tr_touched) {
104 		gfs2_log_release(sdp, tr->tr_reserved);
105 		if (tr->tr_t_gh.gh_gl) {
106 			gfs2_glock_dq(&tr->tr_t_gh);
107 			gfs2_holder_uninit(&tr->tr_t_gh);
108 			kfree(tr);
109 		}
110 		return;
111 	}
112 
113 	if (gfs2_assert_withdraw(sdp, tr->tr_num_buf <= tr->tr_blocks)) {
114 		fs_err(sdp, "tr_num_buf = %u, tr_blocks = %u ",
115 		       tr->tr_num_buf, tr->tr_blocks);
116 		print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
117 	}
118 	if (gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes)) {
119 		fs_err(sdp, "tr_num_revoke = %u, tr_revokes = %u ",
120 		       tr->tr_num_revoke, tr->tr_revokes);
121 		print_symbol(KERN_WARNING "GFS2: Transaction created at: %s\n", tr->tr_ip);
122 	}
123 
124 	gfs2_log_commit(sdp, tr);
125 	if (tr->tr_t_gh.gh_gl) {
126 		gfs2_glock_dq(&tr->tr_t_gh);
127 		gfs2_holder_uninit(&tr->tr_t_gh);
128 		kfree(tr);
129 	}
130 
131 	if (sdp->sd_vfs->s_flags & MS_SYNCHRONOUS)
132 		gfs2_log_flush(sdp, NULL);
133 }
134 
135 /**
136  * gfs2_trans_add_bh - Add a to-be-modified buffer to the current transaction
137  * @gl: the glock the buffer belongs to
138  * @bh: The buffer to add
139  * @meta: True in the case of adding metadata
140  *
141  */
142 
gfs2_trans_add_bh(struct gfs2_glock * gl,struct buffer_head * bh,int meta)143 void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
144 {
145 	struct gfs2_sbd *sdp = gl->gl_sbd;
146 	struct gfs2_bufdata *bd;
147 
148 	lock_buffer(bh);
149 	gfs2_log_lock(sdp);
150 	bd = bh->b_private;
151 	if (bd)
152 		gfs2_assert(sdp, bd->bd_gl == gl);
153 	else {
154 		gfs2_log_unlock(sdp);
155 		unlock_buffer(bh);
156 		gfs2_attach_bufdata(gl, bh, meta);
157 		bd = bh->b_private;
158 		lock_buffer(bh);
159 		gfs2_log_lock(sdp);
160 	}
161 	lops_add(sdp, &bd->bd_le);
162 	gfs2_log_unlock(sdp);
163 	unlock_buffer(bh);
164 }
165 
gfs2_trans_add_revoke(struct gfs2_sbd * sdp,struct gfs2_bufdata * bd)166 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
167 {
168 	BUG_ON(!list_empty(&bd->bd_le.le_list));
169 	BUG_ON(!list_empty(&bd->bd_ail_st_list));
170 	BUG_ON(!list_empty(&bd->bd_ail_gl_list));
171 	lops_init_le(&bd->bd_le, &gfs2_revoke_lops);
172 	lops_add(sdp, &bd->bd_le);
173 }
174 
gfs2_trans_add_unrevoke(struct gfs2_sbd * sdp,u64 blkno,unsigned int len)175 void gfs2_trans_add_unrevoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
176 {
177 	struct gfs2_bufdata *bd, *tmp;
178 	struct gfs2_trans *tr = current->journal_info;
179 	unsigned int n = len;
180 
181 	gfs2_log_lock(sdp);
182 	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_le_revoke, bd_le.le_list) {
183 		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
184 			list_del_init(&bd->bd_le.le_list);
185 			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
186 			sdp->sd_log_num_revoke--;
187 			kmem_cache_free(gfs2_bufdata_cachep, bd);
188 			tr->tr_num_revoke_rm++;
189 			if (--n == 0)
190 				break;
191 		}
192 	}
193 	gfs2_log_unlock(sdp);
194 }
195 
196