1/*
2 * Interface between ext4 and JBD
3 */
4
5#include "ext4_jbd2.h"
6
7#include <trace/events/ext4.h>
8
9/* Just increment the non-pointer handle value */
10static handle_t *ext4_get_nojournal(void)
11{
12	handle_t *handle = current->journal_info;
13	unsigned long ref_cnt = (unsigned long)handle;
14
15	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
16
17	ref_cnt++;
18	handle = (handle_t *)ref_cnt;
19
20	current->journal_info = handle;
21	return handle;
22}
23
24
25/* Decrement the non-pointer handle value */
26static void ext4_put_nojournal(handle_t *handle)
27{
28	unsigned long ref_cnt = (unsigned long)handle;
29
30	BUG_ON(ref_cnt == 0);
31
32	ref_cnt--;
33	handle = (handle_t *)ref_cnt;
34
35	current->journal_info = handle;
36}
37
38/*
39 * Wrappers for jbd2_journal_start/end.
40 */
41static int ext4_journal_check_start(struct super_block *sb)
42{
43	journal_t *journal;
44
45	might_sleep();
46	if (sb->s_flags & MS_RDONLY)
47		return -EROFS;
48	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
49	journal = EXT4_SB(sb)->s_journal;
50	/*
51	 * Special case here: if the journal has aborted behind our
52	 * backs (eg. EIO in the commit thread), then we still need to
53	 * take the FS itself readonly cleanly.
54	 */
55	if (journal && is_journal_aborted(journal)) {
56		ext4_abort(sb, "Detected aborted journal");
57		return -EROFS;
58	}
59	return 0;
60}
61
62handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
63				  int type, int blocks, int rsv_blocks)
64{
65	journal_t *journal;
66	int err;
67
68	trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
69	err = ext4_journal_check_start(sb);
70	if (err < 0)
71		return ERR_PTR(err);
72
73	journal = EXT4_SB(sb)->s_journal;
74	if (!journal)
75		return ext4_get_nojournal();
76	return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
77				   type, line);
78}
79
80int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
81{
82	struct super_block *sb;
83	int err;
84	int rc;
85
86	if (!ext4_handle_valid(handle)) {
87		ext4_put_nojournal(handle);
88		return 0;
89	}
90
91	err = handle->h_err;
92	if (!handle->h_transaction) {
93		rc = jbd2_journal_stop(handle);
94		return err ? err : rc;
95	}
96
97	sb = handle->h_transaction->t_journal->j_private;
98	rc = jbd2_journal_stop(handle);
99
100	if (!err)
101		err = rc;
102	if (err)
103		__ext4_std_error(sb, where, line, err);
104	return err;
105}
106
107handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
108					int type)
109{
110	struct super_block *sb;
111	int err;
112
113	if (!ext4_handle_valid(handle))
114		return ext4_get_nojournal();
115
116	sb = handle->h_journal->j_private;
117	trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
118					  _RET_IP_);
119	err = ext4_journal_check_start(sb);
120	if (err < 0) {
121		jbd2_journal_free_reserved(handle);
122		return ERR_PTR(err);
123	}
124
125	err = jbd2_journal_start_reserved(handle, type, line);
126	if (err < 0)
127		return ERR_PTR(err);
128	return handle;
129}
130
131static void ext4_journal_abort_handle(const char *caller, unsigned int line,
132				      const char *err_fn,
133				      struct buffer_head *bh,
134				      handle_t *handle, int err)
135{
136	char nbuf[16];
137	const char *errstr = ext4_decode_error(NULL, err, nbuf);
138
139	BUG_ON(!ext4_handle_valid(handle));
140
141	if (bh)
142		BUFFER_TRACE(bh, "abort");
143
144	if (!handle->h_err)
145		handle->h_err = err;
146
147	if (is_handle_aborted(handle))
148		return;
149
150	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
151	       caller, line, errstr, err_fn);
152
153	jbd2_journal_abort_handle(handle);
154}
155
156int __ext4_journal_get_write_access(const char *where, unsigned int line,
157				    handle_t *handle, struct buffer_head *bh)
158{
159	int err = 0;
160
161	might_sleep();
162
163	if (ext4_handle_valid(handle)) {
164		err = jbd2_journal_get_write_access(handle, bh);
165		if (err)
166			ext4_journal_abort_handle(where, line, __func__, bh,
167						  handle, err);
168	}
169	return err;
170}
171
172/*
173 * The ext4 forget function must perform a revoke if we are freeing data
174 * which has been journaled.  Metadata (eg. indirect blocks) must be
175 * revoked in all cases.
176 *
177 * "bh" may be NULL: a metadata block may have been freed from memory
178 * but there may still be a record of it in the journal, and that record
179 * still needs to be revoked.
180 *
181 * If the handle isn't valid we're not journaling, but we still need to
182 * call into ext4_journal_revoke() to put the buffer head.
183 */
184int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
185		  int is_metadata, struct inode *inode,
186		  struct buffer_head *bh, ext4_fsblk_t blocknr)
187{
188	int err;
189
190	might_sleep();
191
192	trace_ext4_forget(inode, is_metadata, blocknr);
193	BUFFER_TRACE(bh, "enter");
194
195	jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
196		  "data mode %x\n",
197		  bh, is_metadata, inode->i_mode,
198		  test_opt(inode->i_sb, DATA_FLAGS));
199
200	/* In the no journal case, we can just do a bforget and return */
201	if (!ext4_handle_valid(handle)) {
202		bforget(bh);
203		return 0;
204	}
205
206	/* Never use the revoke function if we are doing full data
207	 * journaling: there is no need to, and a V1 superblock won't
208	 * support it.  Otherwise, only skip the revoke on un-journaled
209	 * data blocks. */
210
211	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
212	    (!is_metadata && !ext4_should_journal_data(inode))) {
213		if (bh) {
214			BUFFER_TRACE(bh, "call jbd2_journal_forget");
215			err = jbd2_journal_forget(handle, bh);
216			if (err)
217				ext4_journal_abort_handle(where, line, __func__,
218							  bh, handle, err);
219			return err;
220		}
221		return 0;
222	}
223
224	/*
225	 * data!=journal && (is_metadata || should_journal_data(inode))
226	 */
227	BUFFER_TRACE(bh, "call jbd2_journal_revoke");
228	err = jbd2_journal_revoke(handle, blocknr, bh);
229	if (err) {
230		ext4_journal_abort_handle(where, line, __func__,
231					  bh, handle, err);
232		__ext4_abort(inode->i_sb, where, line,
233			   "error %d when attempting revoke", err);
234	}
235	BUFFER_TRACE(bh, "exit");
236	return err;
237}
238
239int __ext4_journal_get_create_access(const char *where, unsigned int line,
240				handle_t *handle, struct buffer_head *bh)
241{
242	int err = 0;
243
244	if (ext4_handle_valid(handle)) {
245		err = jbd2_journal_get_create_access(handle, bh);
246		if (err)
247			ext4_journal_abort_handle(where, line, __func__,
248						  bh, handle, err);
249	}
250	return err;
251}
252
253int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
254				 handle_t *handle, struct inode *inode,
255				 struct buffer_head *bh)
256{
257	int err = 0;
258
259	might_sleep();
260
261	set_buffer_meta(bh);
262	set_buffer_prio(bh);
263	if (ext4_handle_valid(handle)) {
264		err = jbd2_journal_dirty_metadata(handle, bh);
265		/* Errors can only happen due to aborted journal or a nasty bug */
266		if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
267			ext4_journal_abort_handle(where, line, __func__, bh,
268						  handle, err);
269			if (inode == NULL) {
270				pr_err("EXT4: jbd2_journal_dirty_metadata "
271				       "failed: handle type %u started at "
272				       "line %u, credits %u/%u, errcode %d",
273				       handle->h_type,
274				       handle->h_line_no,
275				       handle->h_requested_credits,
276				       handle->h_buffer_credits, err);
277				return err;
278			}
279			ext4_error_inode(inode, where, line,
280					 bh->b_blocknr,
281					 "journal_dirty_metadata failed: "
282					 "handle type %u started at line %u, "
283					 "credits %u/%u, errcode %d",
284					 handle->h_type,
285					 handle->h_line_no,
286					 handle->h_requested_credits,
287					 handle->h_buffer_credits, err);
288		}
289	} else {
290		if (inode)
291			mark_buffer_dirty_inode(bh, inode);
292		else
293			mark_buffer_dirty(bh);
294		if (inode && inode_needs_sync(inode)) {
295			sync_dirty_buffer(bh);
296			if (buffer_req(bh) && !buffer_uptodate(bh)) {
297				struct ext4_super_block *es;
298
299				es = EXT4_SB(inode->i_sb)->s_es;
300				es->s_last_error_block =
301					cpu_to_le64(bh->b_blocknr);
302				ext4_error_inode(inode, where, line,
303						 bh->b_blocknr,
304					"IO error syncing itable block");
305				err = -EIO;
306			}
307		}
308	}
309	return err;
310}
311
312int __ext4_handle_dirty_super(const char *where, unsigned int line,
313			      handle_t *handle, struct super_block *sb)
314{
315	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
316	int err = 0;
317
318	ext4_superblock_csum_set(sb);
319	if (ext4_handle_valid(handle)) {
320		err = jbd2_journal_dirty_metadata(handle, bh);
321		if (err)
322			ext4_journal_abort_handle(where, line, __func__,
323						  bh, handle, err);
324	} else
325		mark_buffer_dirty(bh);
326	return err;
327}
328