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TOMOYO Linux Cross Reference
Linux/fs/jbd2/commit.c

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Diff markup

Differences between /fs/jbd2/commit.c (Architecture i386) and /fs/jbd2/commit.c (Architecture m68k)


  1 // SPDX-License-Identifier: GPL-2.0+                1 // SPDX-License-Identifier: GPL-2.0+
  2 /*                                                  2 /*
  3  * linux/fs/jbd2/commit.c                           3  * linux/fs/jbd2/commit.c
  4  *                                                  4  *
  5  * Written by Stephen C. Tweedie <sct@redhat.c      5  * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
  6  *                                                  6  *
  7  * Copyright 1998 Red Hat corp --- All Rights       7  * Copyright 1998 Red Hat corp --- All Rights Reserved
  8  *                                                  8  *
  9  * Journal commit routines for the generic fil      9  * Journal commit routines for the generic filesystem journaling code;
 10  * part of the ext2fs journaling system.           10  * part of the ext2fs journaling system.
 11  */                                                11  */
 12                                                    12 
 13 #include <linux/time.h>                            13 #include <linux/time.h>
 14 #include <linux/fs.h>                              14 #include <linux/fs.h>
 15 #include <linux/jbd2.h>                            15 #include <linux/jbd2.h>
 16 #include <linux/errno.h>                           16 #include <linux/errno.h>
 17 #include <linux/slab.h>                            17 #include <linux/slab.h>
 18 #include <linux/mm.h>                              18 #include <linux/mm.h>
 19 #include <linux/pagemap.h>                         19 #include <linux/pagemap.h>
 20 #include <linux/jiffies.h>                         20 #include <linux/jiffies.h>
 21 #include <linux/crc32.h>                           21 #include <linux/crc32.h>
 22 #include <linux/writeback.h>                       22 #include <linux/writeback.h>
 23 #include <linux/backing-dev.h>                     23 #include <linux/backing-dev.h>
 24 #include <linux/bio.h>                             24 #include <linux/bio.h>
 25 #include <linux/blkdev.h>                          25 #include <linux/blkdev.h>
 26 #include <linux/bitops.h>                          26 #include <linux/bitops.h>
 27 #include <trace/events/jbd2.h>                     27 #include <trace/events/jbd2.h>
 28                                                    28 
 29 /*                                                 29 /*
 30  * IO end handler for temporary buffer_heads h     30  * IO end handler for temporary buffer_heads handling writes to the journal.
 31  */                                                31  */
 32 static void journal_end_buffer_io_sync(struct      32 static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
 33 {                                                  33 {
 34         struct buffer_head *orig_bh = bh->b_pr     34         struct buffer_head *orig_bh = bh->b_private;
 35                                                    35 
 36         BUFFER_TRACE(bh, "");                      36         BUFFER_TRACE(bh, "");
 37         if (uptodate)                              37         if (uptodate)
 38                 set_buffer_uptodate(bh);           38                 set_buffer_uptodate(bh);
 39         else                                       39         else
 40                 clear_buffer_uptodate(bh);         40                 clear_buffer_uptodate(bh);
 41         if (orig_bh) {                             41         if (orig_bh) {
 42                 clear_bit_unlock(BH_Shadow, &o     42                 clear_bit_unlock(BH_Shadow, &orig_bh->b_state);
 43                 smp_mb__after_atomic();            43                 smp_mb__after_atomic();
 44                 wake_up_bit(&orig_bh->b_state,     44                 wake_up_bit(&orig_bh->b_state, BH_Shadow);
 45         }                                          45         }
 46         unlock_buffer(bh);                         46         unlock_buffer(bh);
 47 }                                                  47 }
 48                                                    48 
 49 /*                                                 49 /*
 50  * When an ext4 file is truncated, it is possi     50  * When an ext4 file is truncated, it is possible that some pages are not
 51  * successfully freed, because they are attach     51  * successfully freed, because they are attached to a committing transaction.
 52  * After the transaction commits, these pages      52  * After the transaction commits, these pages are left on the LRU, with no
 53  * ->mapping, and with attached buffers.  Thes     53  * ->mapping, and with attached buffers.  These pages are trivially reclaimable
 54  * by the VM, but their apparent absence upset     54  * by the VM, but their apparent absence upsets the VM accounting, and it makes
 55  * the numbers in /proc/meminfo look odd.          55  * the numbers in /proc/meminfo look odd.
 56  *                                                 56  *
 57  * So here, we have a buffer which has just co     57  * So here, we have a buffer which has just come off the forget list.  Look to
 58  * see if we can strip all buffers from the ba     58  * see if we can strip all buffers from the backing page.
 59  *                                                 59  *
 60  * Called under lock_journal(), and possibly u     60  * Called under lock_journal(), and possibly under journal_datalist_lock.  The
 61  * caller provided us with a ref against the b     61  * caller provided us with a ref against the buffer, and we drop that here.
 62  */                                                62  */
 63 static void release_buffer_page(struct buffer_     63 static void release_buffer_page(struct buffer_head *bh)
 64 {                                                  64 {
 65         struct folio *folio;                       65         struct folio *folio;
 66                                                    66 
 67         if (buffer_dirty(bh))                      67         if (buffer_dirty(bh))
 68                 goto nope;                         68                 goto nope;
 69         if (atomic_read(&bh->b_count) != 1)        69         if (atomic_read(&bh->b_count) != 1)
 70                 goto nope;                         70                 goto nope;
 71         folio = bh->b_folio;                       71         folio = bh->b_folio;
 72         if (folio->mapping)                        72         if (folio->mapping)
 73                 goto nope;                         73                 goto nope;
 74                                                    74 
 75         /* OK, it's a truncated page */            75         /* OK, it's a truncated page */
 76         if (!folio_trylock(folio))                 76         if (!folio_trylock(folio))
 77                 goto nope;                         77                 goto nope;
 78                                                    78 
 79         folio_get(folio);                          79         folio_get(folio);
 80         __brelse(bh);                              80         __brelse(bh);
 81         try_to_free_buffers(folio);                81         try_to_free_buffers(folio);
 82         folio_unlock(folio);                       82         folio_unlock(folio);
 83         folio_put(folio);                          83         folio_put(folio);
 84         return;                                    84         return;
 85                                                    85 
 86 nope:                                              86 nope:
 87         __brelse(bh);                              87         __brelse(bh);
 88 }                                                  88 }
 89                                                    89 
 90 static void jbd2_commit_block_csum_set(journal     90 static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
 91 {                                                  91 {
 92         struct commit_header *h;                   92         struct commit_header *h;
 93         __u32 csum;                                93         __u32 csum;
 94                                                    94 
 95         if (!jbd2_journal_has_csum_v2or3(j))       95         if (!jbd2_journal_has_csum_v2or3(j))
 96                 return;                            96                 return;
 97                                                    97 
 98         h = (struct commit_header *)(bh->b_dat     98         h = (struct commit_header *)(bh->b_data);
 99         h->h_chksum_type = 0;                      99         h->h_chksum_type = 0;
100         h->h_chksum_size = 0;                     100         h->h_chksum_size = 0;
101         h->h_chksum[0] = 0;                       101         h->h_chksum[0] = 0;
102         csum = jbd2_chksum(j, j->j_csum_seed,     102         csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
103         h->h_chksum[0] = cpu_to_be32(csum);       103         h->h_chksum[0] = cpu_to_be32(csum);
104 }                                                 104 }
105                                                   105 
106 /*                                                106 /*
107  * Done it all: now submit the commit record.     107  * Done it all: now submit the commit record.  We should have
108  * cleaned up our previous buffers by now, so     108  * cleaned up our previous buffers by now, so if we are in abort
109  * mode we can now just skip the rest of the j    109  * mode we can now just skip the rest of the journal write
110  * entirely.                                      110  * entirely.
111  *                                                111  *
112  * Returns 1 if the journal needs to be aborte    112  * Returns 1 if the journal needs to be aborted or 0 on success
113  */                                               113  */
114 static int journal_submit_commit_record(journa    114 static int journal_submit_commit_record(journal_t *journal,
115                                         transa    115                                         transaction_t *commit_transaction,
116                                         struct    116                                         struct buffer_head **cbh,
117                                         __u32     117                                         __u32 crc32_sum)
118 {                                                 118 {
119         struct commit_header *tmp;                119         struct commit_header *tmp;
120         struct buffer_head *bh;                   120         struct buffer_head *bh;
121         struct timespec64 now;                    121         struct timespec64 now;
122         blk_opf_t write_flags = REQ_OP_WRITE |    122         blk_opf_t write_flags = REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS;
123                                                   123 
124         *cbh = NULL;                              124         *cbh = NULL;
125                                                   125 
126         if (is_journal_aborted(journal))          126         if (is_journal_aborted(journal))
127                 return 0;                         127                 return 0;
128                                                   128 
129         bh = jbd2_journal_get_descriptor_buffe    129         bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
130                                                   130                                                 JBD2_COMMIT_BLOCK);
131         if (!bh)                                  131         if (!bh)
132                 return 1;                         132                 return 1;
133                                                   133 
134         tmp = (struct commit_header *)bh->b_da    134         tmp = (struct commit_header *)bh->b_data;
135         ktime_get_coarse_real_ts64(&now);         135         ktime_get_coarse_real_ts64(&now);
136         tmp->h_commit_sec = cpu_to_be64(now.tv    136         tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
137         tmp->h_commit_nsec = cpu_to_be32(now.t    137         tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
138                                                   138 
139         if (jbd2_has_feature_checksum(journal)    139         if (jbd2_has_feature_checksum(journal)) {
140                 tmp->h_chksum_type      = JBD2    140                 tmp->h_chksum_type      = JBD2_CRC32_CHKSUM;
141                 tmp->h_chksum_size      = JBD2    141                 tmp->h_chksum_size      = JBD2_CRC32_CHKSUM_SIZE;
142                 tmp->h_chksum[0]        = cpu_    142                 tmp->h_chksum[0]        = cpu_to_be32(crc32_sum);
143         }                                         143         }
144         jbd2_commit_block_csum_set(journal, bh    144         jbd2_commit_block_csum_set(journal, bh);
145                                                   145 
146         BUFFER_TRACE(bh, "submit commit block"    146         BUFFER_TRACE(bh, "submit commit block");
147         lock_buffer(bh);                          147         lock_buffer(bh);
148         clear_buffer_dirty(bh);                   148         clear_buffer_dirty(bh);
149         set_buffer_uptodate(bh);                  149         set_buffer_uptodate(bh);
150         bh->b_end_io = journal_end_buffer_io_s    150         bh->b_end_io = journal_end_buffer_io_sync;
151                                                   151 
152         if (journal->j_flags & JBD2_BARRIER &&    152         if (journal->j_flags & JBD2_BARRIER &&
153             !jbd2_has_feature_async_commit(jou    153             !jbd2_has_feature_async_commit(journal))
154                 write_flags |= REQ_PREFLUSH |     154                 write_flags |= REQ_PREFLUSH | REQ_FUA;
155                                                   155 
156         submit_bh(write_flags, bh);               156         submit_bh(write_flags, bh);
157         *cbh = bh;                                157         *cbh = bh;
158         return 0;                                 158         return 0;
159 }                                                 159 }
160                                                   160 
161 /*                                                161 /*
162  * This function along with journal_submit_com    162  * This function along with journal_submit_commit_record
163  * allows to write the commit record asynchron    163  * allows to write the commit record asynchronously.
164  */                                               164  */
165 static int journal_wait_on_commit_record(journ    165 static int journal_wait_on_commit_record(journal_t *journal,
166                                          struc    166                                          struct buffer_head *bh)
167 {                                                 167 {
168         int ret = 0;                              168         int ret = 0;
169                                                   169 
170         clear_buffer_dirty(bh);                   170         clear_buffer_dirty(bh);
171         wait_on_buffer(bh);                       171         wait_on_buffer(bh);
172                                                   172 
173         if (unlikely(!buffer_uptodate(bh)))       173         if (unlikely(!buffer_uptodate(bh)))
174                 ret = -EIO;                       174                 ret = -EIO;
175         put_bh(bh);            /* One for getb    175         put_bh(bh);            /* One for getblk() */
176                                                   176 
177         return ret;                               177         return ret;
178 }                                                 178 }
179                                                   179 
180 /* Send all the data buffers related to an ino    180 /* Send all the data buffers related to an inode */
181 int jbd2_submit_inode_data(journal_t *journal,    181 int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode)
182 {                                                 182 {
183         if (!jinode || !(jinode->i_flags & JI_    183         if (!jinode || !(jinode->i_flags & JI_WRITE_DATA))
184                 return 0;                         184                 return 0;
185                                                   185 
186         trace_jbd2_submit_inode_data(jinode->i    186         trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
187         return journal->j_submit_inode_data_bu    187         return journal->j_submit_inode_data_buffers(jinode);
188                                                   188 
189 }                                                 189 }
190 EXPORT_SYMBOL(jbd2_submit_inode_data);            190 EXPORT_SYMBOL(jbd2_submit_inode_data);
191                                                   191 
192 int jbd2_wait_inode_data(journal_t *journal, s    192 int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode)
193 {                                                 193 {
194         if (!jinode || !(jinode->i_flags & JI_    194         if (!jinode || !(jinode->i_flags & JI_WAIT_DATA) ||
195                 !jinode->i_vfs_inode || !jinod    195                 !jinode->i_vfs_inode || !jinode->i_vfs_inode->i_mapping)
196                 return 0;                         196                 return 0;
197         return filemap_fdatawait_range_keep_er    197         return filemap_fdatawait_range_keep_errors(
198                 jinode->i_vfs_inode->i_mapping    198                 jinode->i_vfs_inode->i_mapping, jinode->i_dirty_start,
199                 jinode->i_dirty_end);             199                 jinode->i_dirty_end);
200 }                                                 200 }
201 EXPORT_SYMBOL(jbd2_wait_inode_data);              201 EXPORT_SYMBOL(jbd2_wait_inode_data);
202                                                   202 
203 /*                                                203 /*
204  * Submit all the data buffers of inode associ    204  * Submit all the data buffers of inode associated with the transaction to
205  * disk.                                          205  * disk.
206  *                                                206  *
207  * We are in a committing transaction. Therefo    207  * We are in a committing transaction. Therefore no new inode can be added to
208  * our inode list. We use JI_COMMIT_RUNNING fl    208  * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
209  * operate on from being released while we wri    209  * operate on from being released while we write out pages.
210  */                                               210  */
211 static int journal_submit_data_buffers(journal    211 static int journal_submit_data_buffers(journal_t *journal,
212                 transaction_t *commit_transact    212                 transaction_t *commit_transaction)
213 {                                                 213 {
214         struct jbd2_inode *jinode;                214         struct jbd2_inode *jinode;
215         int err, ret = 0;                         215         int err, ret = 0;
216                                                   216 
217         spin_lock(&journal->j_list_lock);         217         spin_lock(&journal->j_list_lock);
218         list_for_each_entry(jinode, &commit_tr    218         list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
219                 if (!(jinode->i_flags & JI_WRI    219                 if (!(jinode->i_flags & JI_WRITE_DATA))
220                         continue;                 220                         continue;
221                 jinode->i_flags |= JI_COMMIT_R    221                 jinode->i_flags |= JI_COMMIT_RUNNING;
222                 spin_unlock(&journal->j_list_l    222                 spin_unlock(&journal->j_list_lock);
223                 /* submit the inode data buffe    223                 /* submit the inode data buffers. */
224                 trace_jbd2_submit_inode_data(j    224                 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
225                 if (journal->j_submit_inode_da    225                 if (journal->j_submit_inode_data_buffers) {
226                         err = journal->j_submi    226                         err = journal->j_submit_inode_data_buffers(jinode);
227                         if (!ret)                 227                         if (!ret)
228                                 ret = err;        228                                 ret = err;
229                 }                                 229                 }
230                 spin_lock(&journal->j_list_loc    230                 spin_lock(&journal->j_list_lock);
231                 J_ASSERT(jinode->i_transaction    231                 J_ASSERT(jinode->i_transaction == commit_transaction);
232                 jinode->i_flags &= ~JI_COMMIT_    232                 jinode->i_flags &= ~JI_COMMIT_RUNNING;
233                 smp_mb();                         233                 smp_mb();
234                 wake_up_bit(&jinode->i_flags,     234                 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
235         }                                         235         }
236         spin_unlock(&journal->j_list_lock);       236         spin_unlock(&journal->j_list_lock);
237         return ret;                               237         return ret;
238 }                                                 238 }
239                                                   239 
240 int jbd2_journal_finish_inode_data_buffers(str    240 int jbd2_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
241 {                                                 241 {
242         struct address_space *mapping = jinode    242         struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
243                                                   243 
244         return filemap_fdatawait_range_keep_er    244         return filemap_fdatawait_range_keep_errors(mapping,
245                                                   245                                                    jinode->i_dirty_start,
246                                                   246                                                    jinode->i_dirty_end);
247 }                                                 247 }
248                                                   248 
249 /*                                                249 /*
250  * Wait for data submitted for writeout, refil    250  * Wait for data submitted for writeout, refile inodes to proper
251  * transaction if needed.                         251  * transaction if needed.
252  *                                                252  *
253  */                                               253  */
254 static int journal_finish_inode_data_buffers(j    254 static int journal_finish_inode_data_buffers(journal_t *journal,
255                 transaction_t *commit_transact    255                 transaction_t *commit_transaction)
256 {                                                 256 {
257         struct jbd2_inode *jinode, *next_i;       257         struct jbd2_inode *jinode, *next_i;
258         int err, ret = 0;                         258         int err, ret = 0;
259                                                   259 
260         /* For locking, see the comment in jou    260         /* For locking, see the comment in journal_submit_data_buffers() */
261         spin_lock(&journal->j_list_lock);         261         spin_lock(&journal->j_list_lock);
262         list_for_each_entry(jinode, &commit_tr    262         list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
263                 if (!(jinode->i_flags & JI_WAI    263                 if (!(jinode->i_flags & JI_WAIT_DATA))
264                         continue;                 264                         continue;
265                 jinode->i_flags |= JI_COMMIT_R    265                 jinode->i_flags |= JI_COMMIT_RUNNING;
266                 spin_unlock(&journal->j_list_l    266                 spin_unlock(&journal->j_list_lock);
267                 /* wait for the inode data buf    267                 /* wait for the inode data buffers writeout. */
268                 if (journal->j_finish_inode_da    268                 if (journal->j_finish_inode_data_buffers) {
269                         err = journal->j_finis    269                         err = journal->j_finish_inode_data_buffers(jinode);
270                         if (!ret)                 270                         if (!ret)
271                                 ret = err;        271                                 ret = err;
272                 }                                 272                 }
273                 cond_resched();                   273                 cond_resched();
274                 spin_lock(&journal->j_list_loc    274                 spin_lock(&journal->j_list_lock);
275                 jinode->i_flags &= ~JI_COMMIT_    275                 jinode->i_flags &= ~JI_COMMIT_RUNNING;
276                 smp_mb();                         276                 smp_mb();
277                 wake_up_bit(&jinode->i_flags,     277                 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
278         }                                         278         }
279                                                   279 
280         /* Now refile inode to proper lists */    280         /* Now refile inode to proper lists */
281         list_for_each_entry_safe(jinode, next_    281         list_for_each_entry_safe(jinode, next_i,
282                                  &commit_trans    282                                  &commit_transaction->t_inode_list, i_list) {
283                 list_del(&jinode->i_list);        283                 list_del(&jinode->i_list);
284                 if (jinode->i_next_transaction    284                 if (jinode->i_next_transaction) {
285                         jinode->i_transaction     285                         jinode->i_transaction = jinode->i_next_transaction;
286                         jinode->i_next_transac    286                         jinode->i_next_transaction = NULL;
287                         list_add(&jinode->i_li    287                         list_add(&jinode->i_list,
288                                 &jinode->i_tra    288                                 &jinode->i_transaction->t_inode_list);
289                 } else {                          289                 } else {
290                         jinode->i_transaction     290                         jinode->i_transaction = NULL;
291                         jinode->i_dirty_start     291                         jinode->i_dirty_start = 0;
292                         jinode->i_dirty_end =     292                         jinode->i_dirty_end = 0;
293                 }                                 293                 }
294         }                                         294         }
295         spin_unlock(&journal->j_list_lock);       295         spin_unlock(&journal->j_list_lock);
296                                                   296 
297         return ret;                               297         return ret;
298 }                                                 298 }
299                                                   299 
300 static __u32 jbd2_checksum_data(__u32 crc32_su    300 static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
301 {                                                 301 {
302         char *addr;                               302         char *addr;
303         __u32 checksum;                           303         __u32 checksum;
304                                                   304 
305         addr = kmap_local_folio(bh->b_folio, b    305         addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
306         checksum = crc32_be(crc32_sum, addr, b    306         checksum = crc32_be(crc32_sum, addr, bh->b_size);
307         kunmap_local(addr);                       307         kunmap_local(addr);
308                                                   308 
309         return checksum;                          309         return checksum;
310 }                                                 310 }
311                                                   311 
312 static void write_tag_block(journal_t *j, jour    312 static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
313                                    unsigned lo    313                                    unsigned long long block)
314 {                                                 314 {
315         tag->t_blocknr = cpu_to_be32(block & (    315         tag->t_blocknr = cpu_to_be32(block & (u32)~0);
316         if (jbd2_has_feature_64bit(j))            316         if (jbd2_has_feature_64bit(j))
317                 tag->t_blocknr_high = cpu_to_b    317                 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
318 }                                                 318 }
319                                                   319 
320 static void jbd2_block_tag_csum_set(journal_t     320 static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
321                                     struct buf    321                                     struct buffer_head *bh, __u32 sequence)
322 {                                                 322 {
323         journal_block_tag3_t *tag3 = (journal_    323         journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
324         __u8 *addr;                               324         __u8 *addr;
325         __u32 csum32;                             325         __u32 csum32;
326         __be32 seq;                               326         __be32 seq;
327                                                   327 
328         if (!jbd2_journal_has_csum_v2or3(j))      328         if (!jbd2_journal_has_csum_v2or3(j))
329                 return;                           329                 return;
330                                                   330 
331         seq = cpu_to_be32(sequence);              331         seq = cpu_to_be32(sequence);
332         addr = kmap_local_folio(bh->b_folio, b    332         addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
333         csum32 = jbd2_chksum(j, j->j_csum_seed    333         csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
334         csum32 = jbd2_chksum(j, csum32, addr,     334         csum32 = jbd2_chksum(j, csum32, addr, bh->b_size);
335         kunmap_local(addr);                       335         kunmap_local(addr);
336                                                   336 
337         if (jbd2_has_feature_csum3(j))            337         if (jbd2_has_feature_csum3(j))
338                 tag3->t_checksum = cpu_to_be32    338                 tag3->t_checksum = cpu_to_be32(csum32);
339         else                                      339         else
340                 tag->t_checksum = cpu_to_be16(    340                 tag->t_checksum = cpu_to_be16(csum32);
341 }                                                 341 }
342 /*                                                342 /*
343  * jbd2_journal_commit_transaction                343  * jbd2_journal_commit_transaction
344  *                                                344  *
345  * The primary function for committing a trans    345  * The primary function for committing a transaction to the log.  This
346  * function is called by the journal thread to    346  * function is called by the journal thread to begin a complete commit.
347  */                                               347  */
348 void jbd2_journal_commit_transaction(journal_t    348 void jbd2_journal_commit_transaction(journal_t *journal)
349 {                                                 349 {
350         struct transaction_stats_s stats;         350         struct transaction_stats_s stats;
351         transaction_t *commit_transaction;        351         transaction_t *commit_transaction;
352         struct journal_head *jh;                  352         struct journal_head *jh;
353         struct buffer_head *descriptor;           353         struct buffer_head *descriptor;
354         struct buffer_head **wbuf = journal->j    354         struct buffer_head **wbuf = journal->j_wbuf;
355         int bufs;                                 355         int bufs;
356         int escape;                               356         int escape;
357         int err;                                  357         int err;
358         unsigned long long blocknr;               358         unsigned long long blocknr;
359         ktime_t start_time;                       359         ktime_t start_time;
360         u64 commit_time;                          360         u64 commit_time;
361         char *tagp = NULL;                        361         char *tagp = NULL;
362         journal_block_tag_t *tag = NULL;          362         journal_block_tag_t *tag = NULL;
363         int space_left = 0;                       363         int space_left = 0;
364         int first_tag = 0;                        364         int first_tag = 0;
365         int tag_flag;                             365         int tag_flag;
366         int i;                                    366         int i;
367         int tag_bytes = journal_tag_bytes(jour    367         int tag_bytes = journal_tag_bytes(journal);
368         struct buffer_head *cbh = NULL; /* For    368         struct buffer_head *cbh = NULL; /* For transactional checksums */
369         __u32 crc32_sum = ~0;                     369         __u32 crc32_sum = ~0;
370         struct blk_plug plug;                     370         struct blk_plug plug;
371         /* Tail of the journal */                 371         /* Tail of the journal */
372         unsigned long first_block;                372         unsigned long first_block;
373         tid_t first_tid;                          373         tid_t first_tid;
374         int update_tail;                          374         int update_tail;
375         int csum_size = 0;                        375         int csum_size = 0;
376         LIST_HEAD(io_bufs);                       376         LIST_HEAD(io_bufs);
377         LIST_HEAD(log_bufs);                      377         LIST_HEAD(log_bufs);
378                                                   378 
379         if (jbd2_journal_has_csum_v2or3(journa    379         if (jbd2_journal_has_csum_v2or3(journal))
380                 csum_size = sizeof(struct jbd2    380                 csum_size = sizeof(struct jbd2_journal_block_tail);
381                                                   381 
382         /*                                        382         /*
383          * First job: lock down the current tr    383          * First job: lock down the current transaction and wait for
384          * all outstanding updates to complete    384          * all outstanding updates to complete.
385          */                                       385          */
386                                                   386 
387         /* Do we need to erase the effects of     387         /* Do we need to erase the effects of a prior jbd2_journal_flush? */
388         if (journal->j_flags & JBD2_FLUSHED) {    388         if (journal->j_flags & JBD2_FLUSHED) {
389                 jbd2_debug(3, "super block upd    389                 jbd2_debug(3, "super block updated\n");
390                 mutex_lock_io(&journal->j_chec    390                 mutex_lock_io(&journal->j_checkpoint_mutex);
391                 /*                                391                 /*
392                  * We hold j_checkpoint_mutex     392                  * We hold j_checkpoint_mutex so tail cannot change under us.
393                  * We don't need any special d    393                  * We don't need any special data guarantees for writing sb
394                  * since journal is empty and     394                  * since journal is empty and it is ok for write to be
395                  * flushed only with transacti    395                  * flushed only with transaction commit.
396                  */                               396                  */
397                 jbd2_journal_update_sb_log_tai    397                 jbd2_journal_update_sb_log_tail(journal,
398                                                   398                                                 journal->j_tail_sequence,
399                                                   399                                                 journal->j_tail, 0);
400                 mutex_unlock(&journal->j_check    400                 mutex_unlock(&journal->j_checkpoint_mutex);
401         } else {                                  401         } else {
402                 jbd2_debug(3, "superblock not     402                 jbd2_debug(3, "superblock not updated\n");
403         }                                         403         }
404                                                   404 
405         J_ASSERT(journal->j_running_transactio    405         J_ASSERT(journal->j_running_transaction != NULL);
406         J_ASSERT(journal->j_committing_transac    406         J_ASSERT(journal->j_committing_transaction == NULL);
407                                                   407 
408         write_lock(&journal->j_state_lock);       408         write_lock(&journal->j_state_lock);
409         journal->j_flags |= JBD2_FULL_COMMIT_O    409         journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
410         while (journal->j_flags & JBD2_FAST_CO    410         while (journal->j_flags & JBD2_FAST_COMMIT_ONGOING) {
411                 DEFINE_WAIT(wait);                411                 DEFINE_WAIT(wait);
412                                                   412 
413                 prepare_to_wait(&journal->j_fc    413                 prepare_to_wait(&journal->j_fc_wait, &wait,
414                                 TASK_UNINTERRU    414                                 TASK_UNINTERRUPTIBLE);
415                 write_unlock(&journal->j_state    415                 write_unlock(&journal->j_state_lock);
416                 schedule();                       416                 schedule();
417                 write_lock(&journal->j_state_l    417                 write_lock(&journal->j_state_lock);
418                 finish_wait(&journal->j_fc_wai    418                 finish_wait(&journal->j_fc_wait, &wait);
419                 /*                                419                 /*
420                  * TODO: by blocking fast comm    420                  * TODO: by blocking fast commits here, we are increasing
421                  * fsync() latency slightly. S    421                  * fsync() latency slightly. Strictly speaking, we don't need
422                  * to block fast commits until    422                  * to block fast commits until the transaction enters T_FLUSH
423                  * state. So an optimization i    423                  * state. So an optimization is possible where we block new fast
424                  * commits here and wait for e    424                  * commits here and wait for existing ones to complete
425                  * just before we enter T_FLUS    425                  * just before we enter T_FLUSH. That way, the existing fast
426                  * commits and this full commi    426                  * commits and this full commit can proceed parallely.
427                  */                               427                  */
428         }                                         428         }
429         write_unlock(&journal->j_state_lock);     429         write_unlock(&journal->j_state_lock);
430                                                   430 
431         commit_transaction = journal->j_runnin    431         commit_transaction = journal->j_running_transaction;
432                                                   432 
433         trace_jbd2_start_commit(journal, commi    433         trace_jbd2_start_commit(journal, commit_transaction);
434         jbd2_debug(1, "JBD2: starting commit o    434         jbd2_debug(1, "JBD2: starting commit of transaction %d\n",
435                         commit_transaction->t_    435                         commit_transaction->t_tid);
436                                                   436 
437         write_lock(&journal->j_state_lock);       437         write_lock(&journal->j_state_lock);
438         journal->j_fc_off = 0;                    438         journal->j_fc_off = 0;
439         J_ASSERT(commit_transaction->t_state =    439         J_ASSERT(commit_transaction->t_state == T_RUNNING);
440         commit_transaction->t_state = T_LOCKED    440         commit_transaction->t_state = T_LOCKED;
441                                                   441 
442         trace_jbd2_commit_locking(journal, com    442         trace_jbd2_commit_locking(journal, commit_transaction);
443         stats.run.rs_wait = commit_transaction    443         stats.run.rs_wait = commit_transaction->t_max_wait;
444         stats.run.rs_request_delay = 0;           444         stats.run.rs_request_delay = 0;
445         stats.run.rs_locked = jiffies;            445         stats.run.rs_locked = jiffies;
446         if (commit_transaction->t_requested)      446         if (commit_transaction->t_requested)
447                 stats.run.rs_request_delay =      447                 stats.run.rs_request_delay =
448                         jbd2_time_diff(commit_    448                         jbd2_time_diff(commit_transaction->t_requested,
449                                        stats.r    449                                        stats.run.rs_locked);
450         stats.run.rs_running = jbd2_time_diff(    450         stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
451                                                   451                                               stats.run.rs_locked);
452                                                   452 
453         // waits for any t_updates to finish      453         // waits for any t_updates to finish
454         jbd2_journal_wait_updates(journal);       454         jbd2_journal_wait_updates(journal);
455                                                   455 
456         commit_transaction->t_state = T_SWITCH    456         commit_transaction->t_state = T_SWITCH;
457                                                   457 
458         J_ASSERT (atomic_read(&commit_transact    458         J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
459                         journal->j_max_transac    459                         journal->j_max_transaction_buffers);
460                                                   460 
461         /*                                        461         /*
462          * First thing we are allowed to do is    462          * First thing we are allowed to do is to discard any remaining
463          * BJ_Reserved buffers.  Note, it is _    463          * BJ_Reserved buffers.  Note, it is _not_ permissible to assume
464          * that there are no such buffers: if     464          * that there are no such buffers: if a large filesystem
465          * operation like a truncate needs to     465          * operation like a truncate needs to split itself over multiple
466          * transactions, then it may try to do    466          * transactions, then it may try to do a jbd2_journal_restart() while
467          * there are still BJ_Reserved buffers    467          * there are still BJ_Reserved buffers outstanding.  These must
468          * be released cleanly from the curren    468          * be released cleanly from the current transaction.
469          *                                        469          *
470          * In this case, the filesystem must s    470          * In this case, the filesystem must still reserve write access
471          * again before modifying the buffer i    471          * again before modifying the buffer in the new transaction, but
472          * we do not require it to remember ex    472          * we do not require it to remember exactly which old buffers it
473          * has reserved.  This is consistent w    473          * has reserved.  This is consistent with the existing behaviour
474          * that multiple jbd2_journal_get_writ    474          * that multiple jbd2_journal_get_write_access() calls to the same
475          * buffer are perfectly permissible.      475          * buffer are perfectly permissible.
476          * We use journal->j_state_lock here t    476          * We use journal->j_state_lock here to serialize processing of
477          * t_reserved_list with eviction of bu    477          * t_reserved_list with eviction of buffers from journal_unmap_buffer().
478          */                                       478          */
479         while (commit_transaction->t_reserved_    479         while (commit_transaction->t_reserved_list) {
480                 jh = commit_transaction->t_res    480                 jh = commit_transaction->t_reserved_list;
481                 JBUFFER_TRACE(jh, "reserved, u    481                 JBUFFER_TRACE(jh, "reserved, unused: refile");
482                 /*                                482                 /*
483                  * A jbd2_journal_get_undo_acc    483                  * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
484                  * leave undo-committed data.     484                  * leave undo-committed data.
485                  */                               485                  */
486                 if (jh->b_committed_data) {       486                 if (jh->b_committed_data) {
487                         struct buffer_head *bh    487                         struct buffer_head *bh = jh2bh(jh);
488                                                   488 
489                         spin_lock(&jh->b_state    489                         spin_lock(&jh->b_state_lock);
490                         jbd2_free(jh->b_commit    490                         jbd2_free(jh->b_committed_data, bh->b_size);
491                         jh->b_committed_data =    491                         jh->b_committed_data = NULL;
492                         spin_unlock(&jh->b_sta    492                         spin_unlock(&jh->b_state_lock);
493                 }                                 493                 }
494                 jbd2_journal_refile_buffer(jou    494                 jbd2_journal_refile_buffer(journal, jh);
495         }                                         495         }
496                                                   496 
497         write_unlock(&journal->j_state_lock);     497         write_unlock(&journal->j_state_lock);
498         /*                                        498         /*
499          * Now try to drop any written-back bu    499          * Now try to drop any written-back buffers from the journal's
500          * checkpoint lists.  We do this *befo    500          * checkpoint lists.  We do this *before* commit because it potentially
501          * frees some memory                      501          * frees some memory
502          */                                       502          */
503         spin_lock(&journal->j_list_lock);         503         spin_lock(&journal->j_list_lock);
504         __jbd2_journal_clean_checkpoint_list(j    504         __jbd2_journal_clean_checkpoint_list(journal, JBD2_SHRINK_BUSY_STOP);
505         spin_unlock(&journal->j_list_lock);       505         spin_unlock(&journal->j_list_lock);
506                                                   506 
507         jbd2_debug(3, "JBD2: commit phase 1\n"    507         jbd2_debug(3, "JBD2: commit phase 1\n");
508                                                   508 
509         /*                                        509         /*
510          * Clear revoked flag to reflect there    510          * Clear revoked flag to reflect there is no revoked buffers
511          * in the next transaction which is go    511          * in the next transaction which is going to be started.
512          */                                       512          */
513         jbd2_clear_buffer_revoked_flags(journa    513         jbd2_clear_buffer_revoked_flags(journal);
514                                                   514 
515         /*                                        515         /*
516          * Switch to a new revoke table.          516          * Switch to a new revoke table.
517          */                                       517          */
518         jbd2_journal_switch_revoke_table(journ    518         jbd2_journal_switch_revoke_table(journal);
519                                                   519 
520         write_lock(&journal->j_state_lock);       520         write_lock(&journal->j_state_lock);
521         /*                                        521         /*
522          * Reserved credits cannot be claimed     522          * Reserved credits cannot be claimed anymore, free them
523          */                                       523          */
524         atomic_sub(atomic_read(&journal->j_res    524         atomic_sub(atomic_read(&journal->j_reserved_credits),
525                    &commit_transaction->t_outs    525                    &commit_transaction->t_outstanding_credits);
526                                                   526 
527         trace_jbd2_commit_flushing(journal, co    527         trace_jbd2_commit_flushing(journal, commit_transaction);
528         stats.run.rs_flushing = jiffies;          528         stats.run.rs_flushing = jiffies;
529         stats.run.rs_locked = jbd2_time_diff(s    529         stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
530                                              s    530                                              stats.run.rs_flushing);
531                                                   531 
532         commit_transaction->t_state = T_FLUSH;    532         commit_transaction->t_state = T_FLUSH;
533         journal->j_committing_transaction = co    533         journal->j_committing_transaction = commit_transaction;
534         journal->j_running_transaction = NULL;    534         journal->j_running_transaction = NULL;
535         start_time = ktime_get();                 535         start_time = ktime_get();
536         commit_transaction->t_log_start = jour    536         commit_transaction->t_log_start = journal->j_head;
537         wake_up_all(&journal->j_wait_transacti    537         wake_up_all(&journal->j_wait_transaction_locked);
538         write_unlock(&journal->j_state_lock);     538         write_unlock(&journal->j_state_lock);
539                                                   539 
540         jbd2_debug(3, "JBD2: commit phase 2a\n    540         jbd2_debug(3, "JBD2: commit phase 2a\n");
541                                                   541 
542         /*                                        542         /*
543          * Now start flushing things to disk,     543          * Now start flushing things to disk, in the order they appear
544          * on the transaction lists.  Data blo    544          * on the transaction lists.  Data blocks go first.
545          */                                       545          */
546         err = journal_submit_data_buffers(jour    546         err = journal_submit_data_buffers(journal, commit_transaction);
547         if (err)                                  547         if (err)
548                 jbd2_journal_abort(journal, er    548                 jbd2_journal_abort(journal, err);
549                                                   549 
550         blk_start_plug(&plug);                    550         blk_start_plug(&plug);
551         jbd2_journal_write_revoke_records(comm    551         jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
552                                                   552 
553         jbd2_debug(3, "JBD2: commit phase 2b\n    553         jbd2_debug(3, "JBD2: commit phase 2b\n");
554                                                   554 
555         /*                                        555         /*
556          * Way to go: we have now written out     556          * Way to go: we have now written out all of the data for a
557          * transaction!  Now comes the tricky     557          * transaction!  Now comes the tricky part: we need to write out
558          * metadata.  Loop over the transactio    558          * metadata.  Loop over the transaction's entire buffer list:
559          */                                       559          */
560         write_lock(&journal->j_state_lock);       560         write_lock(&journal->j_state_lock);
561         commit_transaction->t_state = T_COMMIT    561         commit_transaction->t_state = T_COMMIT;
562         write_unlock(&journal->j_state_lock);     562         write_unlock(&journal->j_state_lock);
563                                                   563 
564         trace_jbd2_commit_logging(journal, com    564         trace_jbd2_commit_logging(journal, commit_transaction);
565         stats.run.rs_logging = jiffies;           565         stats.run.rs_logging = jiffies;
566         stats.run.rs_flushing = jbd2_time_diff    566         stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
567                                                   567                                                stats.run.rs_logging);
568         stats.run.rs_blocks = commit_transacti    568         stats.run.rs_blocks = commit_transaction->t_nr_buffers;
569         stats.run.rs_blocks_logged = 0;           569         stats.run.rs_blocks_logged = 0;
570                                                   570 
571         J_ASSERT(commit_transaction->t_nr_buff    571         J_ASSERT(commit_transaction->t_nr_buffers <=
572                  atomic_read(&commit_transacti    572                  atomic_read(&commit_transaction->t_outstanding_credits));
573                                                   573 
574         bufs = 0;                                 574         bufs = 0;
575         descriptor = NULL;                        575         descriptor = NULL;
576         while (commit_transaction->t_buffers)     576         while (commit_transaction->t_buffers) {
577                                                   577 
578                 /* Find the next buffer to be     578                 /* Find the next buffer to be journaled... */
579                                                   579 
580                 jh = commit_transaction->t_buf    580                 jh = commit_transaction->t_buffers;
581                                                   581 
582                 /* If we're in abort mode, we     582                 /* If we're in abort mode, we just un-journal the buffer and
583                    release it. */                 583                    release it. */
584                                                   584 
585                 if (is_journal_aborted(journal    585                 if (is_journal_aborted(journal)) {
586                         clear_buffer_jbddirty(    586                         clear_buffer_jbddirty(jh2bh(jh));
587                         JBUFFER_TRACE(jh, "jou    587                         JBUFFER_TRACE(jh, "journal is aborting: refile");
588                         jbd2_buffer_abort_trig    588                         jbd2_buffer_abort_trigger(jh,
589                                                   589                                                   jh->b_frozen_data ?
590                                                   590                                                   jh->b_frozen_triggers :
591                                                   591                                                   jh->b_triggers);
592                         jbd2_journal_refile_bu    592                         jbd2_journal_refile_buffer(journal, jh);
593                         /* If that was the las    593                         /* If that was the last one, we need to clean up
594                          * any descriptor buff    594                          * any descriptor buffers which may have been
595                          * already allocated,     595                          * already allocated, even if we are now
596                          * aborting. */           596                          * aborting. */
597                         if (!commit_transactio    597                         if (!commit_transaction->t_buffers)
598                                 goto start_jou    598                                 goto start_journal_io;
599                         continue;                 599                         continue;
600                 }                                 600                 }
601                                                   601 
602                 /* Make sure we have a descrip    602                 /* Make sure we have a descriptor block in which to
603                    record the metadata buffer.    603                    record the metadata buffer. */
604                                                   604 
605                 if (!descriptor) {                605                 if (!descriptor) {
606                         J_ASSERT (bufs == 0);     606                         J_ASSERT (bufs == 0);
607                                                   607 
608                         jbd2_debug(4, "JBD2: g    608                         jbd2_debug(4, "JBD2: get descriptor\n");
609                                                   609 
610                         descriptor = jbd2_jour    610                         descriptor = jbd2_journal_get_descriptor_buffer(
611                                                   611                                                         commit_transaction,
612                                                   612                                                         JBD2_DESCRIPTOR_BLOCK);
613                         if (!descriptor) {        613                         if (!descriptor) {
614                                 jbd2_journal_a    614                                 jbd2_journal_abort(journal, -EIO);
615                                 continue;         615                                 continue;
616                         }                         616                         }
617                                                   617 
618                         jbd2_debug(4, "JBD2: g    618                         jbd2_debug(4, "JBD2: got buffer %llu (%p)\n",
619                                 (unsigned long    619                                 (unsigned long long)descriptor->b_blocknr,
620                                 descriptor->b_    620                                 descriptor->b_data);
621                         tagp = &descriptor->b_    621                         tagp = &descriptor->b_data[sizeof(journal_header_t)];
622                         space_left = descripto    622                         space_left = descriptor->b_size -
623                                                   623                                                 sizeof(journal_header_t);
624                         first_tag = 1;            624                         first_tag = 1;
625                         set_buffer_jwrite(desc    625                         set_buffer_jwrite(descriptor);
626                         set_buffer_dirty(descr    626                         set_buffer_dirty(descriptor);
627                         wbuf[bufs++] = descrip    627                         wbuf[bufs++] = descriptor;
628                                                   628 
629                         /* Record it so that w    629                         /* Record it so that we can wait for IO
630                            completion later */    630                            completion later */
631                         BUFFER_TRACE(descripto    631                         BUFFER_TRACE(descriptor, "ph3: file as descriptor");
632                         jbd2_file_log_bh(&log_    632                         jbd2_file_log_bh(&log_bufs, descriptor);
633                 }                                 633                 }
634                                                   634 
635                 /* Where is the buffer to be w    635                 /* Where is the buffer to be written? */
636                                                   636 
637                 err = jbd2_journal_next_log_bl    637                 err = jbd2_journal_next_log_block(journal, &blocknr);
638                 /* If the block mapping failed    638                 /* If the block mapping failed, just abandon the buffer
639                    and repeat this loop: we'll    639                    and repeat this loop: we'll fall into the
640                    refile-on-abort condition a    640                    refile-on-abort condition above. */
641                 if (err) {                        641                 if (err) {
642                         jbd2_journal_abort(jou    642                         jbd2_journal_abort(journal, err);
643                         continue;                 643                         continue;
644                 }                                 644                 }
645                                                   645 
646                 /*                                646                 /*
647                  * start_this_handle() uses t_    647                  * start_this_handle() uses t_outstanding_credits to determine
648                  * the free space in the log.     648                  * the free space in the log.
649                  */                               649                  */
650                 atomic_dec(&commit_transaction    650                 atomic_dec(&commit_transaction->t_outstanding_credits);
651                                                   651 
652                 /* Bump b_count to prevent tru    652                 /* Bump b_count to prevent truncate from stumbling over
653                    the shadowed buffer!  @@@ T    653                    the shadowed buffer!  @@@ This can go if we ever get
654                    rid of the shadow pairing o    654                    rid of the shadow pairing of buffers. */
655                 atomic_inc(&jh2bh(jh)->b_count    655                 atomic_inc(&jh2bh(jh)->b_count);
656                                                   656 
657                 /*                                657                 /*
658                  * Make a temporary IO buffer     658                  * Make a temporary IO buffer with which to write it out
659                  * (this will requeue the meta    659                  * (this will requeue the metadata buffer to BJ_Shadow).
660                  */                               660                  */
661                 set_bit(BH_JWrite, &jh2bh(jh)-    661                 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
662                 JBUFFER_TRACE(jh, "ph3: write     662                 JBUFFER_TRACE(jh, "ph3: write metadata");
663                 escape = jbd2_journal_write_me    663                 escape = jbd2_journal_write_metadata_buffer(commit_transaction,
664                                                   664                                                 jh, &wbuf[bufs], blocknr);
665                 if (escape < 0) {                 665                 if (escape < 0) {
666                         jbd2_journal_abort(jou    666                         jbd2_journal_abort(journal, escape);
667                         continue;                 667                         continue;
668                 }                                 668                 }
669                 jbd2_file_log_bh(&io_bufs, wbu    669                 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
670                                                   670 
671                 /* Record the new block's tag     671                 /* Record the new block's tag in the current descriptor
672                    buffer */                      672                    buffer */
673                                                   673 
674                 tag_flag = 0;                     674                 tag_flag = 0;
675                 if (escape)                       675                 if (escape)
676                         tag_flag |= JBD2_FLAG_    676                         tag_flag |= JBD2_FLAG_ESCAPE;
677                 if (!first_tag)                   677                 if (!first_tag)
678                         tag_flag |= JBD2_FLAG_    678                         tag_flag |= JBD2_FLAG_SAME_UUID;
679                                                   679 
680                 tag = (journal_block_tag_t *)     680                 tag = (journal_block_tag_t *) tagp;
681                 write_tag_block(journal, tag,     681                 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
682                 tag->t_flags = cpu_to_be16(tag    682                 tag->t_flags = cpu_to_be16(tag_flag);
683                 jbd2_block_tag_csum_set(journa    683                 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
684                                         commit    684                                         commit_transaction->t_tid);
685                 tagp += tag_bytes;                685                 tagp += tag_bytes;
686                 space_left -= tag_bytes;          686                 space_left -= tag_bytes;
687                 bufs++;                           687                 bufs++;
688                                                   688 
689                 if (first_tag) {                  689                 if (first_tag) {
690                         memcpy (tagp, journal-    690                         memcpy (tagp, journal->j_uuid, 16);
691                         tagp += 16;               691                         tagp += 16;
692                         space_left -= 16;         692                         space_left -= 16;
693                         first_tag = 0;            693                         first_tag = 0;
694                 }                                 694                 }
695                                                   695 
696                 /* If there's no more to do, o    696                 /* If there's no more to do, or if the descriptor is full,
697                    let the IO rip! */             697                    let the IO rip! */
698                                                   698 
699                 if (bufs == journal->j_wbufsiz    699                 if (bufs == journal->j_wbufsize ||
700                     commit_transaction->t_buff    700                     commit_transaction->t_buffers == NULL ||
701                     space_left < tag_bytes + 1    701                     space_left < tag_bytes + 16 + csum_size) {
702                                                   702 
703                         jbd2_debug(4, "JBD2: S    703                         jbd2_debug(4, "JBD2: Submit %d IOs\n", bufs);
704                                                   704 
705                         /* Write an end-of-des    705                         /* Write an end-of-descriptor marker before
706                            submitting the IOs.    706                            submitting the IOs.  "tag" still points to
707                            the last tag we set    707                            the last tag we set up. */
708                                                   708 
709                         tag->t_flags |= cpu_to    709                         tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
710 start_journal_io:                                 710 start_journal_io:
711                         if (descriptor)           711                         if (descriptor)
712                                 jbd2_descripto    712                                 jbd2_descriptor_block_csum_set(journal,
713                                                   713                                                         descriptor);
714                                                   714 
715                         for (i = 0; i < bufs;     715                         for (i = 0; i < bufs; i++) {
716                                 struct buffer_    716                                 struct buffer_head *bh = wbuf[i];
717                                                   717 
718                                 /*                718                                 /*
719                                  * Compute che    719                                  * Compute checksum.
720                                  */               720                                  */
721                                 if (jbd2_has_f    721                                 if (jbd2_has_feature_checksum(journal)) {
722                                         crc32_    722                                         crc32_sum =
723                                             jb    723                                             jbd2_checksum_data(crc32_sum, bh);
724                                 }                 724                                 }
725                                                   725 
726                                 lock_buffer(bh    726                                 lock_buffer(bh);
727                                 clear_buffer_d    727                                 clear_buffer_dirty(bh);
728                                 set_buffer_upt    728                                 set_buffer_uptodate(bh);
729                                 bh->b_end_io =    729                                 bh->b_end_io = journal_end_buffer_io_sync;
730                                 submit_bh(REQ_    730                                 submit_bh(REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS,
731                                           bh);    731                                           bh);
732                         }                         732                         }
733                         cond_resched();           733                         cond_resched();
734                                                   734 
735                         /* Force a new descrip    735                         /* Force a new descriptor to be generated next
736                            time round the loop    736                            time round the loop. */
737                         descriptor = NULL;        737                         descriptor = NULL;
738                         bufs = 0;                 738                         bufs = 0;
739                 }                                 739                 }
740         }                                         740         }
741                                                   741 
742         err = journal_finish_inode_data_buffer    742         err = journal_finish_inode_data_buffers(journal, commit_transaction);
743         if (err) {                                743         if (err) {
744                 printk(KERN_WARNING               744                 printk(KERN_WARNING
745                         "JBD2: Detected IO err    745                         "JBD2: Detected IO errors while flushing file data "
746                        "on %s\n", journal->j_d    746                        "on %s\n", journal->j_devname);
747                 if (journal->j_flags & JBD2_AB    747                 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
748                         jbd2_journal_abort(jou    748                         jbd2_journal_abort(journal, err);
749                 err = 0;                          749                 err = 0;
750         }                                         750         }
751                                                   751 
752         /*                                        752         /*
753          * Get current oldest transaction in t    753          * Get current oldest transaction in the log before we issue flush
754          * to the filesystem device. After the    754          * to the filesystem device. After the flush we can be sure that
755          * blocks of all older transactions ar    755          * blocks of all older transactions are checkpointed to persistent
756          * storage and we will be safe to upda    756          * storage and we will be safe to update journal start in the
757          * superblock with the numbers we get     757          * superblock with the numbers we get here.
758          */                                       758          */
759         update_tail =                             759         update_tail =
760                 jbd2_journal_get_log_tail(jour    760                 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
761                                                   761 
762         write_lock(&journal->j_state_lock);       762         write_lock(&journal->j_state_lock);
763         if (update_tail) {                        763         if (update_tail) {
764                 long freed = first_block - jou    764                 long freed = first_block - journal->j_tail;
765                                                   765 
766                 if (first_block < journal->j_t    766                 if (first_block < journal->j_tail)
767                         freed += journal->j_la    767                         freed += journal->j_last - journal->j_first;
768                 /* Update tail only if we free    768                 /* Update tail only if we free significant amount of space */
769                 if (freed < journal->j_max_tra    769                 if (freed < journal->j_max_transaction_buffers)
770                         update_tail = 0;          770                         update_tail = 0;
771         }                                         771         }
772         J_ASSERT(commit_transaction->t_state =    772         J_ASSERT(commit_transaction->t_state == T_COMMIT);
773         commit_transaction->t_state = T_COMMIT    773         commit_transaction->t_state = T_COMMIT_DFLUSH;
774         write_unlock(&journal->j_state_lock);     774         write_unlock(&journal->j_state_lock);
775                                                   775 
776         /*                                        776         /*
777          * If the journal is not located on th    777          * If the journal is not located on the file system device,
778          * then we must flush the file system     778          * then we must flush the file system device before we issue
779          * the commit record                      779          * the commit record
780          */                                       780          */
781         if (commit_transaction->t_need_data_fl    781         if (commit_transaction->t_need_data_flush &&
782             (journal->j_fs_dev != journal->j_d    782             (journal->j_fs_dev != journal->j_dev) &&
783             (journal->j_flags & JBD2_BARRIER))    783             (journal->j_flags & JBD2_BARRIER))
784                 blkdev_issue_flush(journal->j_    784                 blkdev_issue_flush(journal->j_fs_dev);
785                                                   785 
786         /* Done it all: now write the commit r    786         /* Done it all: now write the commit record asynchronously. */
787         if (jbd2_has_feature_async_commit(jour    787         if (jbd2_has_feature_async_commit(journal)) {
788                 err = journal_submit_commit_re    788                 err = journal_submit_commit_record(journal, commit_transaction,
789                                                   789                                                  &cbh, crc32_sum);
790                 if (err)                          790                 if (err)
791                         jbd2_journal_abort(jou    791                         jbd2_journal_abort(journal, err);
792         }                                         792         }
793                                                   793 
794         blk_finish_plug(&plug);                   794         blk_finish_plug(&plug);
795                                                   795 
796         /* Lo and behold: we have just managed    796         /* Lo and behold: we have just managed to send a transaction to
797            the log.  Before we can commit it,     797            the log.  Before we can commit it, wait for the IO so far to
798            complete.  Control buffers being wr    798            complete.  Control buffers being written are on the
799            transaction's t_log_list queue, and    799            transaction's t_log_list queue, and metadata buffers are on
800            the io_bufs list.                      800            the io_bufs list.
801                                                   801 
802            Wait for the buffers in reverse ord    802            Wait for the buffers in reverse order.  That way we are
803            less likely to be woken up until al    803            less likely to be woken up until all IOs have completed, and
804            so we incur less scheduling load.      804            so we incur less scheduling load.
805         */                                        805         */
806                                                   806 
807         jbd2_debug(3, "JBD2: commit phase 3\n"    807         jbd2_debug(3, "JBD2: commit phase 3\n");
808                                                   808 
809         while (!list_empty(&io_bufs)) {           809         while (!list_empty(&io_bufs)) {
810                 struct buffer_head *bh = list_    810                 struct buffer_head *bh = list_entry(io_bufs.prev,
811                                                   811                                                     struct buffer_head,
812                                                   812                                                     b_assoc_buffers);
813                                                   813 
814                 wait_on_buffer(bh);               814                 wait_on_buffer(bh);
815                 cond_resched();                   815                 cond_resched();
816                                                   816 
817                 if (unlikely(!buffer_uptodate(    817                 if (unlikely(!buffer_uptodate(bh)))
818                         err = -EIO;               818                         err = -EIO;
819                 jbd2_unfile_log_bh(bh);           819                 jbd2_unfile_log_bh(bh);
820                 stats.run.rs_blocks_logged++;     820                 stats.run.rs_blocks_logged++;
821                                                   821 
822                 /*                                822                 /*
823                  * The list contains temporary    823                  * The list contains temporary buffer heads created by
824                  * jbd2_journal_write_metadata    824                  * jbd2_journal_write_metadata_buffer().
825                  */                               825                  */
826                 BUFFER_TRACE(bh, "dumping temp    826                 BUFFER_TRACE(bh, "dumping temporary bh");
827                 __brelse(bh);                     827                 __brelse(bh);
828                 J_ASSERT_BH(bh, atomic_read(&b    828                 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
829                 free_buffer_head(bh);             829                 free_buffer_head(bh);
830                                                   830 
831                 /* We also have to refile the     831                 /* We also have to refile the corresponding shadowed buffer */
832                 jh = commit_transaction->t_sha    832                 jh = commit_transaction->t_shadow_list->b_tprev;
833                 bh = jh2bh(jh);                   833                 bh = jh2bh(jh);
834                 clear_buffer_jwrite(bh);          834                 clear_buffer_jwrite(bh);
835                 J_ASSERT_BH(bh, buffer_jbddirt    835                 J_ASSERT_BH(bh, buffer_jbddirty(bh));
836                 J_ASSERT_BH(bh, !buffer_shadow    836                 J_ASSERT_BH(bh, !buffer_shadow(bh));
837                                                   837 
838                 /* The metadata is now release    838                 /* The metadata is now released for reuse, but we need
839                    to remember it against this    839                    to remember it against this transaction so that when
840                    we finally commit, we can d    840                    we finally commit, we can do any checkpointing
841                    required. */                   841                    required. */
842                 JBUFFER_TRACE(jh, "file as BJ_    842                 JBUFFER_TRACE(jh, "file as BJ_Forget");
843                 jbd2_journal_file_buffer(jh, c    843                 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
844                 JBUFFER_TRACE(jh, "brelse shad    844                 JBUFFER_TRACE(jh, "brelse shadowed buffer");
845                 __brelse(bh);                     845                 __brelse(bh);
846         }                                         846         }
847                                                   847 
848         J_ASSERT (commit_transaction->t_shadow    848         J_ASSERT (commit_transaction->t_shadow_list == NULL);
849                                                   849 
850         jbd2_debug(3, "JBD2: commit phase 4\n"    850         jbd2_debug(3, "JBD2: commit phase 4\n");
851                                                   851 
852         /* Here we wait for the revoke record     852         /* Here we wait for the revoke record and descriptor record buffers */
853         while (!list_empty(&log_bufs)) {          853         while (!list_empty(&log_bufs)) {
854                 struct buffer_head *bh;           854                 struct buffer_head *bh;
855                                                   855 
856                 bh = list_entry(log_bufs.prev,    856                 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
857                 wait_on_buffer(bh);               857                 wait_on_buffer(bh);
858                 cond_resched();                   858                 cond_resched();
859                                                   859 
860                 if (unlikely(!buffer_uptodate(    860                 if (unlikely(!buffer_uptodate(bh)))
861                         err = -EIO;               861                         err = -EIO;
862                                                   862 
863                 BUFFER_TRACE(bh, "ph5: control    863                 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
864                 clear_buffer_jwrite(bh);          864                 clear_buffer_jwrite(bh);
865                 jbd2_unfile_log_bh(bh);           865                 jbd2_unfile_log_bh(bh);
866                 stats.run.rs_blocks_logged++;     866                 stats.run.rs_blocks_logged++;
867                 __brelse(bh);           /* One    867                 __brelse(bh);           /* One for getblk */
868                 /* AKPM: bforget here */          868                 /* AKPM: bforget here */
869         }                                         869         }
870                                                   870 
871         if (err)                                  871         if (err)
872                 jbd2_journal_abort(journal, er    872                 jbd2_journal_abort(journal, err);
873                                                   873 
874         jbd2_debug(3, "JBD2: commit phase 5\n"    874         jbd2_debug(3, "JBD2: commit phase 5\n");
875         write_lock(&journal->j_state_lock);       875         write_lock(&journal->j_state_lock);
876         J_ASSERT(commit_transaction->t_state =    876         J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
877         commit_transaction->t_state = T_COMMIT    877         commit_transaction->t_state = T_COMMIT_JFLUSH;
878         write_unlock(&journal->j_state_lock);     878         write_unlock(&journal->j_state_lock);
879                                                   879 
880         if (!jbd2_has_feature_async_commit(jou    880         if (!jbd2_has_feature_async_commit(journal)) {
881                 err = journal_submit_commit_re    881                 err = journal_submit_commit_record(journal, commit_transaction,
882                                                   882                                                 &cbh, crc32_sum);
883                 if (err)                          883                 if (err)
884                         jbd2_journal_abort(jou    884                         jbd2_journal_abort(journal, err);
885         }                                         885         }
886         if (cbh)                                  886         if (cbh)
887                 err = journal_wait_on_commit_r    887                 err = journal_wait_on_commit_record(journal, cbh);
888         stats.run.rs_blocks_logged++;             888         stats.run.rs_blocks_logged++;
889         if (jbd2_has_feature_async_commit(jour    889         if (jbd2_has_feature_async_commit(journal) &&
890             journal->j_flags & JBD2_BARRIER) {    890             journal->j_flags & JBD2_BARRIER) {
891                 blkdev_issue_flush(journal->j_    891                 blkdev_issue_flush(journal->j_dev);
892         }                                         892         }
893                                                   893 
894         if (err)                                  894         if (err)
895                 jbd2_journal_abort(journal, er    895                 jbd2_journal_abort(journal, err);
896                                                   896 
897         WARN_ON_ONCE(                             897         WARN_ON_ONCE(
898                 atomic_read(&commit_transactio    898                 atomic_read(&commit_transaction->t_outstanding_credits) < 0);
899                                                   899 
900         /*                                        900         /*
901          * Now disk caches for filesystem devi    901          * Now disk caches for filesystem device are flushed so we are safe to
902          * erase checkpointed transactions fro    902          * erase checkpointed transactions from the log by updating journal
903          * superblock.                            903          * superblock.
904          */                                       904          */
905         if (update_tail)                          905         if (update_tail)
906                 jbd2_update_log_tail(journal,     906                 jbd2_update_log_tail(journal, first_tid, first_block);
907                                                   907 
908         /* End of a transaction!  Finally, we     908         /* End of a transaction!  Finally, we can do checkpoint
909            processing: any buffers committed a    909            processing: any buffers committed as a result of this
910            transaction can be removed from any    910            transaction can be removed from any checkpoint list it was on
911            before. */                             911            before. */
912                                                   912 
913         jbd2_debug(3, "JBD2: commit phase 6\n"    913         jbd2_debug(3, "JBD2: commit phase 6\n");
914                                                   914 
915         J_ASSERT(list_empty(&commit_transactio    915         J_ASSERT(list_empty(&commit_transaction->t_inode_list));
916         J_ASSERT(commit_transaction->t_buffers    916         J_ASSERT(commit_transaction->t_buffers == NULL);
917         J_ASSERT(commit_transaction->t_checkpo    917         J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
918         J_ASSERT(commit_transaction->t_shadow_    918         J_ASSERT(commit_transaction->t_shadow_list == NULL);
919                                                   919 
920 restart_loop:                                     920 restart_loop:
921         /*                                        921         /*
922          * As there are other places (journal_    922          * As there are other places (journal_unmap_buffer()) adding buffers
923          * to this list we have to be careful     923          * to this list we have to be careful and hold the j_list_lock.
924          */                                       924          */
925         spin_lock(&journal->j_list_lock);         925         spin_lock(&journal->j_list_lock);
926         while (commit_transaction->t_forget) {    926         while (commit_transaction->t_forget) {
927                 transaction_t *cp_transaction;    927                 transaction_t *cp_transaction;
928                 struct buffer_head *bh;           928                 struct buffer_head *bh;
929                 int try_to_free = 0;              929                 int try_to_free = 0;
930                 bool drop_ref;                    930                 bool drop_ref;
931                                                   931 
932                 jh = commit_transaction->t_for    932                 jh = commit_transaction->t_forget;
933                 spin_unlock(&journal->j_list_l    933                 spin_unlock(&journal->j_list_lock);
934                 bh = jh2bh(jh);                   934                 bh = jh2bh(jh);
935                 /*                                935                 /*
936                  * Get a reference so that bh     936                  * Get a reference so that bh cannot be freed before we are
937                  * done with it.                  937                  * done with it.
938                  */                               938                  */
939                 get_bh(bh);                       939                 get_bh(bh);
940                 spin_lock(&jh->b_state_lock);     940                 spin_lock(&jh->b_state_lock);
941                 J_ASSERT_JH(jh, jh->b_transact    941                 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
942                                                   942 
943                 /*                                943                 /*
944                  * If there is undo-protected     944                  * If there is undo-protected committed data against
945                  * this buffer, then we can re    945                  * this buffer, then we can remove it now.  If it is a
946                  * buffer needing such protect    946                  * buffer needing such protection, the old frozen_data
947                  * field now points to a commi    947                  * field now points to a committed version of the
948                  * buffer, so rotate that fiel    948                  * buffer, so rotate that field to the new committed
949                  * data.                          949                  * data.
950                  *                                950                  *
951                  * Otherwise, we can just thro    951                  * Otherwise, we can just throw away the frozen data now.
952                  *                                952                  *
953                  * We also know that the froze    953                  * We also know that the frozen data has already fired
954                  * its triggers if they exist,    954                  * its triggers if they exist, so we can clear that too.
955                  */                               955                  */
956                 if (jh->b_committed_data) {       956                 if (jh->b_committed_data) {
957                         jbd2_free(jh->b_commit    957                         jbd2_free(jh->b_committed_data, bh->b_size);
958                         jh->b_committed_data =    958                         jh->b_committed_data = NULL;
959                         if (jh->b_frozen_data)    959                         if (jh->b_frozen_data) {
960                                 jh->b_committe    960                                 jh->b_committed_data = jh->b_frozen_data;
961                                 jh->b_frozen_d    961                                 jh->b_frozen_data = NULL;
962                                 jh->b_frozen_t    962                                 jh->b_frozen_triggers = NULL;
963                         }                         963                         }
964                 } else if (jh->b_frozen_data)     964                 } else if (jh->b_frozen_data) {
965                         jbd2_free(jh->b_frozen    965                         jbd2_free(jh->b_frozen_data, bh->b_size);
966                         jh->b_frozen_data = NU    966                         jh->b_frozen_data = NULL;
967                         jh->b_frozen_triggers     967                         jh->b_frozen_triggers = NULL;
968                 }                                 968                 }
969                                                   969 
970                 spin_lock(&journal->j_list_loc    970                 spin_lock(&journal->j_list_lock);
971                 cp_transaction = jh->b_cp_tran    971                 cp_transaction = jh->b_cp_transaction;
972                 if (cp_transaction) {             972                 if (cp_transaction) {
973                         JBUFFER_TRACE(jh, "rem    973                         JBUFFER_TRACE(jh, "remove from old cp transaction");
974                         cp_transaction->t_chp_    974                         cp_transaction->t_chp_stats.cs_dropped++;
975                         __jbd2_journal_remove_    975                         __jbd2_journal_remove_checkpoint(jh);
976                 }                                 976                 }
977                                                   977 
978                 /* Only re-checkpoint the buff    978                 /* Only re-checkpoint the buffer_head if it is marked
979                  * dirty.  If the buffer was a    979                  * dirty.  If the buffer was added to the BJ_Forget list
980                  * by jbd2_journal_forget, it     980                  * by jbd2_journal_forget, it may no longer be dirty and
981                  * there's no point in keeping    981                  * there's no point in keeping a checkpoint record for
982                  * it. */                         982                  * it. */
983                                                   983 
984                 /*                                984                 /*
985                  * A buffer which has been fre    985                  * A buffer which has been freed while still being journaled
986                  * by a previous transaction,     986                  * by a previous transaction, refile the buffer to BJ_Forget of
987                  * the running transaction. If    987                  * the running transaction. If the just committed transaction
988                  * contains "add to orphan" op    988                  * contains "add to orphan" operation, we can completely
989                  * invalidate the buffer now.     989                  * invalidate the buffer now. We are rather through in that
990                  * since the buffer may be sti    990                  * since the buffer may be still accessible when blocksize <
991                  * pagesize and it is attached    991                  * pagesize and it is attached to the last partial page.
992                  */                               992                  */
993                 if (buffer_freed(bh) && !jh->b    993                 if (buffer_freed(bh) && !jh->b_next_transaction) {
994                         struct address_space *    994                         struct address_space *mapping;
995                                                   995 
996                         clear_buffer_freed(bh)    996                         clear_buffer_freed(bh);
997                         clear_buffer_jbddirty(    997                         clear_buffer_jbddirty(bh);
998                                                   998 
999                         /*                        999                         /*
1000                          * Block device buffe    1000                          * Block device buffers need to stay mapped all the
1001                          * time, so it is eno    1001                          * time, so it is enough to clear buffer_jbddirty and
1002                          * buffer_freed bits.    1002                          * buffer_freed bits. For the file mapping buffers (i.e.
1003                          * journalled data) w    1003                          * journalled data) we need to unmap buffer and clear
1004                          * more bits. We also    1004                          * more bits. We also need to be careful about the check
1005                          * because the data p    1005                          * because the data page mapping can get cleared under
1006                          * our hands. Note th    1006                          * our hands. Note that if mapping == NULL, we don't
1007                          * need to make buffe    1007                          * need to make buffer unmapped because the page is
1008                          * already detached f    1008                          * already detached from the mapping and buffers cannot
1009                          * get reused.           1009                          * get reused.
1010                          */                      1010                          */
1011                         mapping = READ_ONCE(b    1011                         mapping = READ_ONCE(bh->b_folio->mapping);
1012                         if (mapping && !sb_is    1012                         if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
1013                                 clear_buffer_    1013                                 clear_buffer_mapped(bh);
1014                                 clear_buffer_    1014                                 clear_buffer_new(bh);
1015                                 clear_buffer_    1015                                 clear_buffer_req(bh);
1016                                 bh->b_bdev =     1016                                 bh->b_bdev = NULL;
1017                         }                        1017                         }
1018                 }                                1018                 }
1019                                                  1019 
1020                 if (buffer_jbddirty(bh)) {       1020                 if (buffer_jbddirty(bh)) {
1021                         JBUFFER_TRACE(jh, "ad    1021                         JBUFFER_TRACE(jh, "add to new checkpointing trans");
1022                         __jbd2_journal_insert    1022                         __jbd2_journal_insert_checkpoint(jh, commit_transaction);
1023                         if (is_journal_aborte    1023                         if (is_journal_aborted(journal))
1024                                 clear_buffer_    1024                                 clear_buffer_jbddirty(bh);
1025                 } else {                         1025                 } else {
1026                         J_ASSERT_BH(bh, !buff    1026                         J_ASSERT_BH(bh, !buffer_dirty(bh));
1027                         /*                       1027                         /*
1028                          * The buffer on BJ_F    1028                          * The buffer on BJ_Forget list and not jbddirty means
1029                          * it has been freed     1029                          * it has been freed by this transaction and hence it
1030                          * could not have bee    1030                          * could not have been reallocated until this
1031                          * transaction has co    1031                          * transaction has committed. *BUT* it could be
1032                          * reallocated once w    1032                          * reallocated once we have written all the data to
1033                          * disk and before we    1033                          * disk and before we process the buffer on BJ_Forget
1034                          * list.                 1034                          * list.
1035                          */                      1035                          */
1036                         if (!jh->b_next_trans    1036                         if (!jh->b_next_transaction)
1037                                 try_to_free =    1037                                 try_to_free = 1;
1038                 }                                1038                 }
1039                 JBUFFER_TRACE(jh, "refile or     1039                 JBUFFER_TRACE(jh, "refile or unfile buffer");
1040                 drop_ref = __jbd2_journal_ref    1040                 drop_ref = __jbd2_journal_refile_buffer(jh);
1041                 spin_unlock(&jh->b_state_lock    1041                 spin_unlock(&jh->b_state_lock);
1042                 if (drop_ref)                    1042                 if (drop_ref)
1043                         jbd2_journal_put_jour    1043                         jbd2_journal_put_journal_head(jh);
1044                 if (try_to_free)                 1044                 if (try_to_free)
1045                         release_buffer_page(b    1045                         release_buffer_page(bh);        /* Drops bh reference */
1046                 else                             1046                 else
1047                         __brelse(bh);            1047                         __brelse(bh);
1048                 cond_resched_lock(&journal->j    1048                 cond_resched_lock(&journal->j_list_lock);
1049         }                                        1049         }
1050         spin_unlock(&journal->j_list_lock);      1050         spin_unlock(&journal->j_list_lock);
1051         /*                                       1051         /*
1052          * This is a bit sleazy.  We use j_li    1052          * This is a bit sleazy.  We use j_list_lock to protect transition
1053          * of a transaction into T_FINISHED s    1053          * of a transaction into T_FINISHED state and calling
1054          * __jbd2_journal_drop_transaction().    1054          * __jbd2_journal_drop_transaction(). Otherwise we could race with
1055          * other checkpointing code processin    1055          * other checkpointing code processing the transaction...
1056          */                                      1056          */
1057         write_lock(&journal->j_state_lock);      1057         write_lock(&journal->j_state_lock);
1058         spin_lock(&journal->j_list_lock);        1058         spin_lock(&journal->j_list_lock);
1059         /*                                       1059         /*
1060          * Now recheck if some buffers did no    1060          * Now recheck if some buffers did not get attached to the transaction
1061          * while the lock was dropped...         1061          * while the lock was dropped...
1062          */                                      1062          */
1063         if (commit_transaction->t_forget) {      1063         if (commit_transaction->t_forget) {
1064                 spin_unlock(&journal->j_list_    1064                 spin_unlock(&journal->j_list_lock);
1065                 write_unlock(&journal->j_stat    1065                 write_unlock(&journal->j_state_lock);
1066                 goto restart_loop;               1066                 goto restart_loop;
1067         }                                        1067         }
1068                                                  1068 
1069         /* Add the transaction to the checkpo    1069         /* Add the transaction to the checkpoint list
1070          * __journal_remove_checkpoint() can     1070          * __journal_remove_checkpoint() can not destroy transaction
1071          * under us because it is not marked     1071          * under us because it is not marked as T_FINISHED yet */
1072         if (journal->j_checkpoint_transaction    1072         if (journal->j_checkpoint_transactions == NULL) {
1073                 journal->j_checkpoint_transac    1073                 journal->j_checkpoint_transactions = commit_transaction;
1074                 commit_transaction->t_cpnext     1074                 commit_transaction->t_cpnext = commit_transaction;
1075                 commit_transaction->t_cpprev     1075                 commit_transaction->t_cpprev = commit_transaction;
1076         } else {                                 1076         } else {
1077                 commit_transaction->t_cpnext     1077                 commit_transaction->t_cpnext =
1078                         journal->j_checkpoint    1078                         journal->j_checkpoint_transactions;
1079                 commit_transaction->t_cpprev     1079                 commit_transaction->t_cpprev =
1080                         commit_transaction->t    1080                         commit_transaction->t_cpnext->t_cpprev;
1081                 commit_transaction->t_cpnext-    1081                 commit_transaction->t_cpnext->t_cpprev =
1082                         commit_transaction;      1082                         commit_transaction;
1083                 commit_transaction->t_cpprev-    1083                 commit_transaction->t_cpprev->t_cpnext =
1084                                 commit_transa    1084                                 commit_transaction;
1085         }                                        1085         }
1086         spin_unlock(&journal->j_list_lock);      1086         spin_unlock(&journal->j_list_lock);
1087                                                  1087 
1088         /* Done with this transaction! */        1088         /* Done with this transaction! */
1089                                                  1089 
1090         jbd2_debug(3, "JBD2: commit phase 7\n    1090         jbd2_debug(3, "JBD2: commit phase 7\n");
1091                                                  1091 
1092         J_ASSERT(commit_transaction->t_state     1092         J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1093                                                  1093 
1094         commit_transaction->t_start = jiffies    1094         commit_transaction->t_start = jiffies;
1095         stats.run.rs_logging = jbd2_time_diff    1095         stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1096                                                  1096                                               commit_transaction->t_start);
1097                                                  1097 
1098         /*                                       1098         /*
1099          * File the transaction statistics       1099          * File the transaction statistics
1100          */                                      1100          */
1101         stats.ts_tid = commit_transaction->t_    1101         stats.ts_tid = commit_transaction->t_tid;
1102         stats.run.rs_handle_count =              1102         stats.run.rs_handle_count =
1103                 atomic_read(&commit_transacti    1103                 atomic_read(&commit_transaction->t_handle_count);
1104         trace_jbd2_run_stats(journal->j_fs_de    1104         trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1105                              commit_transacti    1105                              commit_transaction->t_tid, &stats.run);
1106         stats.ts_requested = (commit_transact    1106         stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1107                                                  1107 
1108         commit_transaction->t_state = T_COMMI    1108         commit_transaction->t_state = T_COMMIT_CALLBACK;
1109         J_ASSERT(commit_transaction == journa    1109         J_ASSERT(commit_transaction == journal->j_committing_transaction);
1110         WRITE_ONCE(journal->j_commit_sequence    1110         WRITE_ONCE(journal->j_commit_sequence, commit_transaction->t_tid);
1111         journal->j_committing_transaction = N    1111         journal->j_committing_transaction = NULL;
1112         commit_time = ktime_to_ns(ktime_sub(k    1112         commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1113                                                  1113 
1114         /*                                       1114         /*
1115          * weight the commit time higher than    1115          * weight the commit time higher than the average time so we don't
1116          * react too strongly to vast changes    1116          * react too strongly to vast changes in the commit time
1117          */                                      1117          */
1118         if (likely(journal->j_average_commit_    1118         if (likely(journal->j_average_commit_time))
1119                 journal->j_average_commit_tim    1119                 journal->j_average_commit_time = (commit_time +
1120                                 journal->j_av    1120                                 journal->j_average_commit_time*3) / 4;
1121         else                                     1121         else
1122                 journal->j_average_commit_tim    1122                 journal->j_average_commit_time = commit_time;
1123                                                  1123 
1124         write_unlock(&journal->j_state_lock);    1124         write_unlock(&journal->j_state_lock);
1125                                                  1125 
1126         if (journal->j_commit_callback)          1126         if (journal->j_commit_callback)
1127                 journal->j_commit_callback(jo    1127                 journal->j_commit_callback(journal, commit_transaction);
1128         if (journal->j_fc_cleanup_callback)      1128         if (journal->j_fc_cleanup_callback)
1129                 journal->j_fc_cleanup_callbac    1129                 journal->j_fc_cleanup_callback(journal, 1, commit_transaction->t_tid);
1130                                                  1130 
1131         trace_jbd2_end_commit(journal, commit    1131         trace_jbd2_end_commit(journal, commit_transaction);
1132         jbd2_debug(1, "JBD2: commit %d comple    1132         jbd2_debug(1, "JBD2: commit %d complete, head %d\n",
1133                   journal->j_commit_sequence,    1133                   journal->j_commit_sequence, journal->j_tail_sequence);
1134                                                  1134 
1135         write_lock(&journal->j_state_lock);      1135         write_lock(&journal->j_state_lock);
1136         journal->j_flags &= ~JBD2_FULL_COMMIT    1136         journal->j_flags &= ~JBD2_FULL_COMMIT_ONGOING;
1137         journal->j_flags &= ~JBD2_FAST_COMMIT    1137         journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
1138         spin_lock(&journal->j_list_lock);        1138         spin_lock(&journal->j_list_lock);
1139         commit_transaction->t_state = T_FINIS    1139         commit_transaction->t_state = T_FINISHED;
1140         /* Check if the transaction can be dr    1140         /* Check if the transaction can be dropped now that we are finished */
1141         if (commit_transaction->t_checkpoint_    1141         if (commit_transaction->t_checkpoint_list == NULL) {
1142                 __jbd2_journal_drop_transacti    1142                 __jbd2_journal_drop_transaction(journal, commit_transaction);
1143                 jbd2_journal_free_transaction    1143                 jbd2_journal_free_transaction(commit_transaction);
1144         }                                        1144         }
1145         spin_unlock(&journal->j_list_lock);      1145         spin_unlock(&journal->j_list_lock);
1146         write_unlock(&journal->j_state_lock);    1146         write_unlock(&journal->j_state_lock);
1147         wake_up(&journal->j_wait_done_commit)    1147         wake_up(&journal->j_wait_done_commit);
1148         wake_up(&journal->j_fc_wait);            1148         wake_up(&journal->j_fc_wait);
1149                                                  1149 
1150         /*                                       1150         /*
1151          * Calculate overall stats               1151          * Calculate overall stats
1152          */                                      1152          */
1153         spin_lock(&journal->j_history_lock);     1153         spin_lock(&journal->j_history_lock);
1154         journal->j_stats.ts_tid++;               1154         journal->j_stats.ts_tid++;
1155         journal->j_stats.ts_requested += stat    1155         journal->j_stats.ts_requested += stats.ts_requested;
1156         journal->j_stats.run.rs_wait += stats    1156         journal->j_stats.run.rs_wait += stats.run.rs_wait;
1157         journal->j_stats.run.rs_request_delay    1157         journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1158         journal->j_stats.run.rs_running += st    1158         journal->j_stats.run.rs_running += stats.run.rs_running;
1159         journal->j_stats.run.rs_locked += sta    1159         journal->j_stats.run.rs_locked += stats.run.rs_locked;
1160         journal->j_stats.run.rs_flushing += s    1160         journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1161         journal->j_stats.run.rs_logging += st    1161         journal->j_stats.run.rs_logging += stats.run.rs_logging;
1162         journal->j_stats.run.rs_handle_count     1162         journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1163         journal->j_stats.run.rs_blocks += sta    1163         journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1164         journal->j_stats.run.rs_blocks_logged    1164         journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1165         spin_unlock(&journal->j_history_lock)    1165         spin_unlock(&journal->j_history_lock);
1166 }                                                1166 }
1167                                                  1167 

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