xref: /linux/fs/gfs2/trans.c (revision 6dfafbd0299a60bfb5d5e277fdf100037c7ded07)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/sched.h>
10 #include <linux/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/kallsyms.h>
15 #include <linux/gfs2_ondisk.h>
16 
17 #include "gfs2.h"
18 #include "incore.h"
19 #include "glock.h"
20 #include "inode.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 static void gfs2_print_trans(struct gfs2_sbd *sdp, const struct gfs2_trans *tr)
29 {
30 	fs_warn(sdp, "Transaction created at: %pSR\n", (void *)tr->tr_ip);
31 	fs_warn(sdp, "blocks=%u revokes=%u reserved=%u touched=%u\n",
32 		tr->tr_blocks, tr->tr_revokes, tr->tr_reserved,
33 		test_bit(TR_TOUCHED, &tr->tr_flags));
34 	fs_warn(sdp, "Buf %u/%u Databuf %u/%u Revoke %u\n",
35 		tr->tr_num_buf_new, tr->tr_num_buf_rm,
36 		tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
37 		tr->tr_num_revoke);
38 }
39 
40 int __gfs2_trans_begin(struct gfs2_trans *tr, struct gfs2_sbd *sdp,
41 		       unsigned int blocks, unsigned int revokes,
42 		       unsigned long ip)
43 {
44 	unsigned int extra_revokes;
45 
46 	if (current->journal_info) {
47 		gfs2_print_trans(sdp, current->journal_info);
48 		BUG();
49 	}
50 	BUG_ON(blocks == 0 && revokes == 0);
51 
52 	if (gfs2_withdrawn(sdp))
53 		return -EROFS;
54 
55 	tr->tr_ip = ip;
56 	tr->tr_blocks = blocks;
57 	tr->tr_revokes = revokes;
58 	tr->tr_reserved = GFS2_LOG_FLUSH_MIN_BLOCKS;
59 	if (blocks) {
60 		/*
61 		 * The reserved blocks are either used for data or metadata.
62 		 * We can have mixed data and metadata, each with its own log
63 		 * descriptor block; see calc_reserved().
64 		 */
65 		tr->tr_reserved += blocks + 1 + DIV_ROUND_UP(blocks - 1, databuf_limit(sdp));
66 	}
67 	INIT_LIST_HEAD(&tr->tr_databuf);
68 	INIT_LIST_HEAD(&tr->tr_buf);
69 	INIT_LIST_HEAD(&tr->tr_list);
70 	INIT_LIST_HEAD(&tr->tr_ail1_list);
71 	INIT_LIST_HEAD(&tr->tr_ail2_list);
72 
73 	if (gfs2_assert_warn(sdp, tr->tr_reserved <= sdp->sd_jdesc->jd_blocks))
74 		return -EINVAL;
75 
76 	sb_start_intwrite(sdp->sd_vfs);
77 
78 	/*
79 	 * Try the reservations under sd_log_flush_lock to prevent log flushes
80 	 * from creating inconsistencies between the number of allocated and
81 	 * reserved revokes.  If that fails, do a full-block allocation outside
82 	 * of the lock to avoid stalling log flushes.  Then, allot the
83 	 * appropriate number of blocks to revokes, use as many revokes locally
84 	 * as needed, and "release" the surplus into the revokes pool.
85 	 */
86 
87 	down_read(&sdp->sd_log_flush_lock);
88 	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)))
89 		goto out_not_live;
90 	if (gfs2_log_try_reserve(sdp, tr, &extra_revokes))
91 		goto reserved;
92 
93 	up_read(&sdp->sd_log_flush_lock);
94 	gfs2_log_reserve(sdp, tr, &extra_revokes);
95 	down_read(&sdp->sd_log_flush_lock);
96 	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
97 		revokes = tr->tr_revokes + extra_revokes;
98 		gfs2_log_release_revokes(sdp, revokes);
99 		gfs2_log_release(sdp, tr->tr_reserved);
100 		goto out_not_live;
101 	}
102 
103 reserved:
104 	gfs2_log_release_revokes(sdp, extra_revokes);
105 	current->journal_info = tr;
106 	return 0;
107 
108 out_not_live:
109 	up_read(&sdp->sd_log_flush_lock);
110 	sb_end_intwrite(sdp->sd_vfs);
111 	return -EROFS;
112 }
113 
114 int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
115 		     unsigned int revokes)
116 {
117 	struct gfs2_trans *tr;
118 	int error;
119 
120 	tr = kmem_cache_zalloc(gfs2_trans_cachep, GFP_NOFS);
121 	if (!tr)
122 		return -ENOMEM;
123 	error = __gfs2_trans_begin(tr, sdp, blocks, revokes, _RET_IP_);
124 	if (error)
125 		kmem_cache_free(gfs2_trans_cachep, tr);
126 	return error;
127 }
128 
129 void gfs2_trans_end(struct gfs2_sbd *sdp)
130 {
131 	struct gfs2_trans *tr = current->journal_info;
132 	s64 nbuf;
133 
134 	current->journal_info = NULL;
135 
136 	if (!test_bit(TR_TOUCHED, &tr->tr_flags)) {
137 		gfs2_log_release_revokes(sdp, tr->tr_revokes);
138 		up_read(&sdp->sd_log_flush_lock);
139 		gfs2_log_release(sdp, tr->tr_reserved);
140 		if (!test_bit(TR_ONSTACK, &tr->tr_flags))
141 			gfs2_trans_free(sdp, tr);
142 		sb_end_intwrite(sdp->sd_vfs);
143 		return;
144 	}
145 
146 	gfs2_log_release_revokes(sdp, tr->tr_revokes - tr->tr_num_revoke);
147 
148 	nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
149 	nbuf -= tr->tr_num_buf_rm;
150 	nbuf -= tr->tr_num_databuf_rm;
151 
152 	if (gfs2_assert_withdraw(sdp, nbuf <= tr->tr_blocks) ||
153 	    gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes))
154 		gfs2_print_trans(sdp, tr);
155 
156 	gfs2_log_commit(sdp, tr);
157 	if (!test_bit(TR_ONSTACK, &tr->tr_flags) &&
158 	    !test_bit(TR_ATTACHED, &tr->tr_flags))
159 		gfs2_trans_free(sdp, tr);
160 	up_read(&sdp->sd_log_flush_lock);
161 
162 	if (sdp->sd_vfs->s_flags & SB_SYNCHRONOUS)
163 		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
164 			       GFS2_LFC_TRANS_END);
165 	sb_end_intwrite(sdp->sd_vfs);
166 }
167 
168 static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
169 					       struct buffer_head *bh)
170 {
171 	struct gfs2_bufdata *bd;
172 
173 	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
174 	bd->bd_bh = bh;
175 	bd->bd_gl = gl;
176 	INIT_LIST_HEAD(&bd->bd_list);
177 	INIT_LIST_HEAD(&bd->bd_ail_st_list);
178 	INIT_LIST_HEAD(&bd->bd_ail_gl_list);
179 	bh->b_private = bd;
180 	return bd;
181 }
182 
183 /**
184  * gfs2_trans_add_data - Add a databuf to the transaction.
185  * @gl: The inode glock associated with the buffer
186  * @bh: The buffer to add
187  *
188  * This is used in journaled data mode.
189  * We need to journal the data block in the same way as metadata in
190  * the functions above. The difference is that here we have a tag
191  * which is two __be64's being the block number (as per meta data)
192  * and a flag which says whether the data block needs escaping or
193  * not. This means we need a new log entry for each 251 or so data
194  * blocks, which isn't an enormous overhead but twice as much as
195  * for normal metadata blocks.
196  */
197 void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
198 {
199 	struct gfs2_trans *tr = current->journal_info;
200 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
201 	struct gfs2_bufdata *bd;
202 
203 	lock_buffer(bh);
204 	if (buffer_pinned(bh)) {
205 		set_bit(TR_TOUCHED, &tr->tr_flags);
206 		goto out;
207 	}
208 	gfs2_log_lock(sdp);
209 	bd = bh->b_private;
210 	if (bd == NULL) {
211 		gfs2_log_unlock(sdp);
212 		unlock_buffer(bh);
213 		if (bh->b_private == NULL)
214 			bd = gfs2_alloc_bufdata(gl, bh);
215 		else
216 			bd = bh->b_private;
217 		lock_buffer(bh);
218 		gfs2_log_lock(sdp);
219 	}
220 	gfs2_assert(sdp, bd->bd_gl == gl);
221 	set_bit(TR_TOUCHED, &tr->tr_flags);
222 	if (list_empty(&bd->bd_list)) {
223 		set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
224 		set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
225 		gfs2_pin(sdp, bd->bd_bh);
226 		tr->tr_num_databuf_new++;
227 		list_add_tail(&bd->bd_list, &tr->tr_databuf);
228 	}
229 	gfs2_log_unlock(sdp);
230 out:
231 	unlock_buffer(bh);
232 }
233 
234 void gfs2_trans_add_databufs(struct gfs2_glock *gl, struct folio *folio,
235 			     size_t from, size_t len)
236 {
237 	struct buffer_head *head = folio_buffers(folio);
238 	unsigned int bsize = head->b_size;
239 	struct buffer_head *bh;
240 	size_t to = from + len;
241 	size_t start, end;
242 
243 	for (bh = head, start = 0; bh != head || !start;
244 	     bh = bh->b_this_page, start = end) {
245 		end = start + bsize;
246 		if (end <= from)
247 			continue;
248 		if (start >= to)
249 			break;
250 		set_buffer_uptodate(bh);
251 		gfs2_trans_add_data(gl, bh);
252 	}
253 }
254 
255 void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
256 {
257 
258 	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
259 	struct super_block *sb = sdp->sd_vfs;
260 	struct gfs2_bufdata *bd;
261 	struct gfs2_meta_header *mh;
262 	struct gfs2_trans *tr = current->journal_info;
263 
264 	lock_buffer(bh);
265 	if (buffer_pinned(bh)) {
266 		set_bit(TR_TOUCHED, &tr->tr_flags);
267 		goto out;
268 	}
269 	gfs2_log_lock(sdp);
270 	bd = bh->b_private;
271 	if (bd == NULL) {
272 		gfs2_log_unlock(sdp);
273 		unlock_buffer(bh);
274 		folio_lock(bh->b_folio);
275 		if (bh->b_private == NULL)
276 			bd = gfs2_alloc_bufdata(gl, bh);
277 		else
278 			bd = bh->b_private;
279 		folio_unlock(bh->b_folio);
280 		lock_buffer(bh);
281 		gfs2_log_lock(sdp);
282 	}
283 	gfs2_assert(sdp, bd->bd_gl == gl);
284 	set_bit(TR_TOUCHED, &tr->tr_flags);
285 	if (!list_empty(&bd->bd_list))
286 		goto out_unlock;
287 	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
288 	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
289 	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
290 	if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {
291 		fs_err(sdp, "Attempting to add uninitialised block to "
292 		       "journal (inplace block=%lld)\n",
293 		       (unsigned long long)bd->bd_bh->b_blocknr);
294 		BUG();
295 	}
296 	if (gfs2_withdrawn(sdp)) {
297 		fs_info(sdp, "GFS2:adding buf while withdrawn! 0x%llx\n",
298 			(unsigned long long)bd->bd_bh->b_blocknr);
299 		goto out_unlock;
300 	}
301 	if (unlikely(sb->s_writers.frozen == SB_FREEZE_COMPLETE)) {
302 		fs_info(sdp, "GFS2:adding buf while frozen\n");
303 		gfs2_withdraw(sdp);
304 		goto out_unlock;
305 	}
306 	gfs2_pin(sdp, bd->bd_bh);
307 	mh->__pad0 = cpu_to_be64(0);
308 	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
309 	list_add(&bd->bd_list, &tr->tr_buf);
310 	tr->tr_num_buf_new++;
311 out_unlock:
312 	gfs2_log_unlock(sdp);
313 out:
314 	unlock_buffer(bh);
315 }
316 
317 void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
318 {
319 	struct gfs2_trans *tr = current->journal_info;
320 
321 	BUG_ON(!list_empty(&bd->bd_list));
322 	gfs2_add_revoke(sdp, bd);
323 	set_bit(TR_TOUCHED, &tr->tr_flags);
324 	tr->tr_num_revoke++;
325 }
326 
327 void gfs2_trans_remove_revoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
328 {
329 	struct gfs2_bufdata *bd, *tmp;
330 	unsigned int n = len;
331 
332 	gfs2_log_lock(sdp);
333 	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_revokes, bd_list) {
334 		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
335 			list_del_init(&bd->bd_list);
336 			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
337 			sdp->sd_log_num_revoke--;
338 			if (bd->bd_gl)
339 				gfs2_glock_remove_revoke(bd->bd_gl);
340 			kmem_cache_free(gfs2_bufdata_cachep, bd);
341 			gfs2_log_release_revokes(sdp, 1);
342 			if (--n == 0)
343 				break;
344 		}
345 	}
346 	gfs2_log_unlock(sdp);
347 }
348 
349 void gfs2_trans_free(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
350 {
351 	if (tr == NULL)
352 		return;
353 
354 	gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
355 	gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
356 	gfs2_assert_warn(sdp, list_empty(&tr->tr_databuf));
357 	gfs2_assert_warn(sdp, list_empty(&tr->tr_buf));
358 	kmem_cache_free(gfs2_trans_cachep, tr);
359 }
360