Merge branches 'arm/rockchip', 'arm/exynos', 'arm/smmu', 'x86/vt-d', 'x86/amd', ...
[sfrench/cifs-2.6.git] / fs / ext4 / ext4_jbd2.c
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 */
10 static 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 */
26 static 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  */
41 static 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
62 handle_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
80 int __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         if (!handle->h_transaction) {
92                 err = jbd2_journal_stop(handle);
93                 return handle->h_err ? handle->h_err : err;
94         }
95
96         sb = handle->h_transaction->t_journal->j_private;
97         err = handle->h_err;
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
107 handle_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
131 static 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
156 int __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  */
184 int __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
239 int __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
253 int __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
312 int __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 }