blob: 5109f1d5e7ffcbe2eb08340221439b440fd5ba57 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3 */
4
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/time.h>
6#include <linux/reiserfs_fs.h>
7#include <linux/reiserfs_acl.h>
8#include <linux/reiserfs_xattr.h>
9#include <linux/smp_lock.h>
10#include <asm/uaccess.h>
11#include <linux/pagemap.h>
12#include <linux/swap.h>
13#include <linux/writeback.h>
14#include <linux/blkdev.h>
15#include <linux/buffer_head.h>
16#include <linux/quotaops.h>
17
18/*
19** We pack the tails of files on file close, not at the time they are written.
20** This implies an unnecessary copy of the tail and an unnecessary indirect item
21** insertion/balancing, for files that are written in one write.
22** It avoids unnecessary tail packings (balances) for files that are written in
23** multiple writes and are small enough to have tails.
24**
25** file_release is called by the VFS layer when the file is closed. If
26** this is the last open file descriptor, and the file
27** small enough to have a tail, and the tail is currently in an
28** unformatted node, the tail is converted back into a direct item.
29**
30** We use reiserfs_truncate_file to pack the tail, since it already has
31** all the conditions coded.
32*/
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070033static int reiserfs_file_release(struct inode *inode, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034{
35
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070036 struct reiserfs_transaction_handle th;
37 int err;
38 int jbegin_failure = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Eric Sesterhenn14a61442006-10-03 23:36:38 +020040 BUG_ON(!S_ISREG(inode->i_mode));
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070042 /* fast out for when nothing needs to be done */
43 if ((atomic_read(&inode->i_count) > 1 ||
44 !(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) ||
45 !tail_has_to_be_packed(inode)) &&
46 REISERFS_I(inode)->i_prealloc_count <= 0) {
47 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070049
Jes Sorensen1b1dcc12006-01-09 15:59:24 -080050 mutex_lock(&inode->i_mutex);
Vladimir Savelievde145692007-01-22 20:40:46 -080051
52 mutex_lock(&(REISERFS_I(inode)->i_mmap));
53 if (REISERFS_I(inode)->i_flags & i_ever_mapped)
54 REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
55
Chris Masonb5f39532006-08-05 12:15:08 -070056 reiserfs_write_lock(inode->i_sb);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070057 /* freeing preallocation only involves relogging blocks that
58 * are already in the current transaction. preallocation gets
59 * freed at the end of each transaction, so it is impossible for
60 * us to log any additional blocks (including quota blocks)
61 */
62 err = journal_begin(&th, inode->i_sb, 1);
63 if (err) {
64 /* uh oh, we can't allow the inode to go away while there
65 * is still preallocation blocks pending. Try to join the
66 * aborted transaction
67 */
68 jbegin_failure = err;
69 err = journal_join_abort(&th, inode->i_sb, 1);
70
71 if (err) {
72 /* hmpf, our choices here aren't good. We can pin the inode
73 * which will disallow unmount from every happening, we can
74 * do nothing, which will corrupt random memory on unmount,
75 * or we can forcibly remove the file from the preallocation
76 * list, which will leak blocks on disk. Lets pin the inode
77 * and let the admin know what is going on.
78 */
79 igrab(inode);
80 reiserfs_warning(inode->i_sb,
81 "pinning inode %lu because the "
Alexey Dobriyan533221f2006-11-25 11:09:30 -080082 "preallocation can't be freed",
83 inode->i_ino);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070084 goto out;
85 }
86 }
87 reiserfs_update_inode_transaction(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
89#ifdef REISERFS_PREALLOCATE
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070090 reiserfs_discard_prealloc(&th, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#endif
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070092 err = journal_end(&th, inode->i_sb, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070094 /* copy back the error code from journal_begin */
95 if (!err)
96 err = jbegin_failure;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Linus Torvaldsbd4c6252005-07-12 20:21:28 -070098 if (!err && atomic_read(&inode->i_count) <= 1 &&
99 (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) &&
100 tail_has_to_be_packed(inode)) {
101 /* if regular file is released by last holder and it has been
102 appended (we append by unformatted node only) or its direct
103 item(s) had to be converted, then it may have to be
104 indirect2direct converted */
105 err = reiserfs_truncate_file(inode, 0);
106 }
107 out:
Vladimir Savelievde145692007-01-22 20:40:46 -0800108 mutex_unlock(&(REISERFS_I(inode)->i_mmap));
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800109 mutex_unlock(&inode->i_mutex);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700110 reiserfs_write_unlock(inode->i_sb);
111 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112}
113
Vladimir Savelievde145692007-01-22 20:40:46 -0800114static int reiserfs_file_mmap(struct file *file, struct vm_area_struct *vma)
115{
116 struct inode *inode;
117
118 inode = file->f_path.dentry->d_inode;
119 mutex_lock(&(REISERFS_I(inode)->i_mmap));
120 REISERFS_I(inode)->i_flags |= i_ever_mapped;
121 mutex_unlock(&(REISERFS_I(inode)->i_mmap));
122
123 return generic_file_mmap(file, vma);
124}
125
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700126static void reiserfs_vfs_truncate_file(struct inode *inode)
127{
128 reiserfs_truncate_file(inode, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129}
130
131/* Sync a reiserfs file. */
132
133/*
134 * FIXME: sync_mapping_buffers() never has anything to sync. Can
135 * be removed...
136 */
137
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700138static int reiserfs_sync_file(struct file *p_s_filp,
139 struct dentry *p_s_dentry, int datasync)
140{
141 struct inode *p_s_inode = p_s_dentry->d_inode;
142 int n_err;
143 int barrier_done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Eric Sesterhenn14a61442006-10-03 23:36:38 +0200145 BUG_ON(!S_ISREG(p_s_inode->i_mode));
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700146 n_err = sync_mapping_buffers(p_s_inode->i_mapping);
147 reiserfs_write_lock(p_s_inode->i_sb);
148 barrier_done = reiserfs_commit_for_inode(p_s_inode);
149 reiserfs_write_unlock(p_s_inode->i_sb);
Chris Mason25736b12006-09-29 01:59:54 -0700150 if (barrier_done != 1 && reiserfs_barrier_flush(p_s_inode->i_sb))
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700151 blkdev_issue_flush(p_s_inode->i_sb->s_bdev, NULL);
152 if (barrier_done < 0)
153 return barrier_done;
154 return (n_err < 0) ? -EIO : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157/* I really do not want to play with memory shortage right now, so
158 to simplify the code, we are not going to write more than this much pages at
159 a time. This still should considerably improve performance compared to 4k
160 at a time case. This is 32 pages of 4k size. */
161#define REISERFS_WRITE_PAGES_AT_A_TIME (128 * 1024) / PAGE_CACHE_SIZE
162
163/* Allocates blocks for a file to fulfil write request.
164 Maps all unmapped but prepared pages from the list.
165 Updates metadata with newly allocated blocknumbers as needed */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700166static int reiserfs_allocate_blocks_for_region(struct reiserfs_transaction_handle *th, struct inode *inode, /* Inode we work with */
167 loff_t pos, /* Writing position */
168 int num_pages, /* number of pages write going
169 to touch */
170 int write_bytes, /* amount of bytes to write */
171 struct page **prepared_pages, /* array of
172 prepared pages
173 */
174 int blocks_to_allocate /* Amount of blocks we
175 need to allocate to
176 fit the data into file
177 */
178 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700180 struct cpu_key key; // cpu key of item that we are going to deal with
181 struct item_head *ih; // pointer to item head that we are going to deal with
182 struct buffer_head *bh; // Buffer head that contains items that we are going to deal with
183 __le32 *item; // pointer to item we are going to deal with
184 INITIALIZE_PATH(path); // path to item, that we are going to deal with.
185 b_blocknr_t *allocated_blocks; // Pointer to a place where allocated blocknumbers would be stored.
186 reiserfs_blocknr_hint_t hint; // hint structure for block allocator.
187 size_t res; // return value of various functions that we call.
188 int curr_block; // current block used to keep track of unmapped blocks.
189 int i; // loop counter
190 int itempos; // position in item
191 unsigned int from = (pos & (PAGE_CACHE_SIZE - 1)); // writing position in
192 // first page
193 unsigned int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1; /* last modified byte offset in last page */
194 __u64 hole_size; // amount of blocks for a file hole, if it needed to be created.
195 int modifying_this_item = 0; // Flag for items traversal code to keep track
196 // of the fact that we already prepared
197 // current block for journal
198 int will_prealloc = 0;
199 RFALSE(!blocks_to_allocate,
200 "green-9004: tried to allocate zero blocks?");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700202 /* only preallocate if this is a small write */
203 if (REISERFS_I(inode)->i_prealloc_count ||
204 (!(write_bytes & (inode->i_sb->s_blocksize - 1)) &&
205 blocks_to_allocate <
206 REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize))
207 will_prealloc =
208 REISERFS_SB(inode->i_sb)->s_alloc_options.preallocsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700210 allocated_blocks = kmalloc((blocks_to_allocate + will_prealloc) *
211 sizeof(b_blocknr_t), GFP_NOFS);
Diego Callejae5dd2592006-02-01 03:06:44 -0800212 if (!allocated_blocks)
213 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700215 /* First we compose a key to point at the writing position, we want to do
216 that outside of any locking region. */
217 make_cpu_key(&key, inode, pos + 1, TYPE_ANY, 3 /*key length */ );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700219 /* If we came here, it means we absolutely need to open a transaction,
220 since we need to allocate some blocks */
221 reiserfs_write_lock(inode->i_sb); // Journaling stuff and we need that.
222 res = journal_begin(th, inode->i_sb, JOURNAL_PER_BALANCE_CNT * 3 + 1 + 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb)); // Wish I know if this number enough
223 if (res)
224 goto error_exit;
225 reiserfs_update_inode_transaction(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700227 /* Look for the in-tree position of our write, need path for block allocator */
228 res = search_for_position_by_key(inode->i_sb, &key, &path);
229 if (res == IO_ERROR) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 res = -EIO;
231 goto error_exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700234 /* Allocate blocks */
235 /* First fill in "hint" structure for block allocator */
236 hint.th = th; // transaction handle.
237 hint.path = &path; // Path, so that block allocator can determine packing locality or whatever it needs to determine.
238 hint.inode = inode; // Inode is needed by block allocator too.
239 hint.search_start = 0; // We have no hint on where to search free blocks for block allocator.
240 hint.key = key.on_disk_key; // on disk key of file.
241 hint.block = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); // Number of disk blocks this file occupies already.
242 hint.formatted_node = 0; // We are allocating blocks for unformatted node.
243 hint.preallocate = will_prealloc;
244
245 /* Call block allocator to allocate blocks */
246 res =
247 reiserfs_allocate_blocknrs(&hint, allocated_blocks,
248 blocks_to_allocate, blocks_to_allocate);
249 if (res != CARRY_ON) {
250 if (res == NO_DISK_SPACE) {
251 /* We flush the transaction in case of no space. This way some
252 blocks might become free */
253 SB_JOURNAL(inode->i_sb)->j_must_wait = 1;
254 res = restart_transaction(th, inode, &path);
255 if (res)
256 goto error_exit;
257
258 /* We might have scheduled, so search again */
259 res =
260 search_for_position_by_key(inode->i_sb, &key,
261 &path);
262 if (res == IO_ERROR) {
263 res = -EIO;
264 goto error_exit;
265 }
266
267 /* update changed info for hint structure. */
268 res =
269 reiserfs_allocate_blocknrs(&hint, allocated_blocks,
270 blocks_to_allocate,
271 blocks_to_allocate);
272 if (res != CARRY_ON) {
Jan Kara0ad74ff2005-11-08 21:34:58 -0800273 res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC;
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700274 pathrelse(&path);
275 goto error_exit;
276 }
277 } else {
Jan Kara0ad74ff2005-11-08 21:34:58 -0800278 res = res == QUOTA_EXCEEDED ? -EDQUOT : -ENOSPC;
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700279 pathrelse(&path);
280 goto error_exit;
281 }
282 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283#ifdef __BIG_ENDIAN
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700284 // Too bad, I have not found any way to convert a given region from
285 // cpu format to little endian format
286 {
287 int i;
288 for (i = 0; i < blocks_to_allocate; i++)
289 allocated_blocks[i] = cpu_to_le32(allocated_blocks[i]);
290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291#endif
292
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700293 /* Blocks allocating well might have scheduled and tree might have changed,
294 let's search the tree again */
295 /* find where in the tree our write should go */
296 res = search_for_position_by_key(inode->i_sb, &key, &path);
297 if (res == IO_ERROR) {
298 res = -EIO;
299 goto error_exit_free_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 }
301
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700302 bh = get_last_bh(&path); // Get a bufferhead for last element in path.
303 ih = get_ih(&path); // Get a pointer to last item head in path.
304 item = get_item(&path); // Get a pointer to last item in path
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700306 /* Let's see what we have found */
307 if (res != POSITION_FOUND) { /* position not found, this means that we
308 might need to append file with holes
309 first */
310 // Since we are writing past the file's end, we need to find out if
311 // there is a hole that needs to be inserted before our writing
312 // position, and how many blocks it is going to cover (we need to
313 // populate pointers to file blocks representing the hole with zeros)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700315 {
316 int item_offset = 1;
317 /*
318 * if ih is stat data, its offset is 0 and we don't want to
319 * add 1 to pos in the hole_size calculation
320 */
321 if (is_statdata_le_ih(ih))
322 item_offset = 0;
323 hole_size = (pos + item_offset -
324 (le_key_k_offset
325 (get_inode_item_key_version(inode),
326 &(ih->ih_key)) + op_bytes_number(ih,
327 inode->
328 i_sb->
329 s_blocksize)))
330 >> inode->i_sb->s_blocksize_bits;
331 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700333 if (hole_size > 0) {
334 int to_paste = min_t(__u64, hole_size, MAX_ITEM_LEN(inode->i_sb->s_blocksize) / UNFM_P_SIZE); // How much data to insert first time.
335 /* area filled with zeroes, to supply as list of zero blocknumbers
336 We allocate it outside of loop just in case loop would spin for
337 several iterations. */
Yan Burman01afb212006-12-06 20:39:01 -0800338 char *zeros = kzalloc(to_paste * UNFM_P_SIZE, GFP_ATOMIC); // We cannot insert more than MAX_ITEM_LEN bytes anyway.
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700339 if (!zeros) {
340 res = -ENOMEM;
341 goto error_exit_free_blocks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700343 do {
344 to_paste =
345 min_t(__u64, hole_size,
346 MAX_ITEM_LEN(inode->i_sb->
347 s_blocksize) /
348 UNFM_P_SIZE);
349 if (is_indirect_le_ih(ih)) {
350 /* Ok, there is existing indirect item already. Need to append it */
351 /* Calculate position past inserted item */
352 make_cpu_key(&key, inode,
353 le_key_k_offset
354 (get_inode_item_key_version
355 (inode),
356 &(ih->ih_key)) +
357 op_bytes_number(ih,
358 inode->
359 i_sb->
360 s_blocksize),
361 TYPE_INDIRECT, 3);
362 res =
363 reiserfs_paste_into_item(th, &path,
364 &key,
365 inode,
366 (char *)
367 zeros,
368 UNFM_P_SIZE
369 *
370 to_paste);
371 if (res) {
372 kfree(zeros);
373 goto error_exit_free_blocks;
374 }
375 } else if (is_statdata_le_ih(ih)) {
376 /* No existing item, create it */
377 /* item head for new item */
378 struct item_head ins_ih;
379
380 /* create a key for our new item */
381 make_cpu_key(&key, inode, 1,
382 TYPE_INDIRECT, 3);
383
384 /* Create new item head for our new item */
385 make_le_item_head(&ins_ih, &key,
386 key.version, 1,
387 TYPE_INDIRECT,
388 to_paste *
389 UNFM_P_SIZE,
390 0 /* free space */ );
391
392 /* Find where such item should live in the tree */
393 res =
394 search_item(inode->i_sb, &key,
395 &path);
396 if (res != ITEM_NOT_FOUND) {
397 /* item should not exist, otherwise we have error */
398 if (res != -ENOSPC) {
399 reiserfs_warning(inode->
400 i_sb,
401 "green-9008: search_by_key (%K) returned %d",
402 &key,
403 res);
404 }
405 res = -EIO;
406 kfree(zeros);
407 goto error_exit_free_blocks;
408 }
409 res =
410 reiserfs_insert_item(th, &path,
411 &key, &ins_ih,
412 inode,
413 (char *)zeros);
414 } else {
415 reiserfs_panic(inode->i_sb,
416 "green-9011: Unexpected key type %K\n",
417 &key);
418 }
419 if (res) {
420 kfree(zeros);
421 goto error_exit_free_blocks;
422 }
423 /* Now we want to check if transaction is too full, and if it is
424 we restart it. This will also free the path. */
425 if (journal_transaction_should_end
426 (th, th->t_blocks_allocated)) {
Vladimir V. Savelievc5574762006-12-06 20:39:12 -0800427 inode->i_size = cpu_key_k_offset(&key) +
428 (to_paste << inode->i_blkbits);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700429 res =
430 restart_transaction(th, inode,
431 &path);
432 if (res) {
433 pathrelse(&path);
434 kfree(zeros);
435 goto error_exit;
436 }
437 }
438
439 /* Well, need to recalculate path and stuff */
440 set_cpu_key_k_offset(&key,
441 cpu_key_k_offset(&key) +
442 (to_paste << inode->
443 i_blkbits));
444 res =
445 search_for_position_by_key(inode->i_sb,
446 &key, &path);
447 if (res == IO_ERROR) {
448 res = -EIO;
449 kfree(zeros);
450 goto error_exit_free_blocks;
451 }
452 bh = get_last_bh(&path);
453 ih = get_ih(&path);
454 item = get_item(&path);
455 hole_size -= to_paste;
456 } while (hole_size);
457 kfree(zeros);
458 }
459 }
460 // Go through existing indirect items first
461 // replace all zeroes with blocknumbers from list
462 // Note that if no corresponding item was found, by previous search,
463 // it means there are no existing in-tree representation for file area
464 // we are going to overwrite, so there is nothing to scan through for holes.
465 for (curr_block = 0, itempos = path.pos_in_item;
466 curr_block < blocks_to_allocate && res == POSITION_FOUND;) {
467 retry:
468
469 if (itempos >= ih_item_len(ih) / UNFM_P_SIZE) {
470 /* We run out of data in this indirect item, let's look for another
471 one. */
472 /* First if we are already modifying current item, log it */
473 if (modifying_this_item) {
474 journal_mark_dirty(th, inode->i_sb, bh);
475 modifying_this_item = 0;
476 }
477 /* Then set the key to look for a new indirect item (offset of old
478 item is added to old item length */
479 set_cpu_key_k_offset(&key,
480 le_key_k_offset
481 (get_inode_item_key_version(inode),
482 &(ih->ih_key)) +
483 op_bytes_number(ih,
484 inode->i_sb->
485 s_blocksize));
486 /* Search ofor position of new key in the tree. */
487 res =
488 search_for_position_by_key(inode->i_sb, &key,
489 &path);
490 if (res == IO_ERROR) {
491 res = -EIO;
492 goto error_exit_free_blocks;
493 }
494 bh = get_last_bh(&path);
495 ih = get_ih(&path);
496 item = get_item(&path);
497 itempos = path.pos_in_item;
498 continue; // loop to check all kinds of conditions and so on.
499 }
500 /* Ok, we have correct position in item now, so let's see if it is
501 representing file hole (blocknumber is zero) and fill it if needed */
502 if (!item[itempos]) {
503 /* Ok, a hole. Now we need to check if we already prepared this
504 block to be journaled */
505 while (!modifying_this_item) { // loop until succeed
506 /* Well, this item is not journaled yet, so we must prepare
507 it for journal first, before we can change it */
508 struct item_head tmp_ih; // We copy item head of found item,
509 // here to detect if fs changed under
510 // us while we were preparing for
511 // journal.
512 int fs_gen; // We store fs generation here to find if someone
513 // changes fs under our feet
514
515 copy_item_head(&tmp_ih, ih); // Remember itemhead
516 fs_gen = get_generation(inode->i_sb); // remember fs generation
517 reiserfs_prepare_for_journal(inode->i_sb, bh, 1); // Prepare a buffer within which indirect item is stored for changing.
518 if (fs_changed(fs_gen, inode->i_sb)
519 && item_moved(&tmp_ih, &path)) {
520 // Sigh, fs was changed under us, we need to look for new
521 // location of item we are working with
522
523 /* unmark prepaerd area as journaled and search for it's
524 new position */
525 reiserfs_restore_prepared_buffer(inode->
526 i_sb,
527 bh);
528 res =
529 search_for_position_by_key(inode->
530 i_sb,
531 &key,
532 &path);
533 if (res == IO_ERROR) {
534 res = -EIO;
535 goto error_exit_free_blocks;
536 }
537 bh = get_last_bh(&path);
538 ih = get_ih(&path);
539 item = get_item(&path);
540 itempos = path.pos_in_item;
541 goto retry;
542 }
543 modifying_this_item = 1;
544 }
545 item[itempos] = allocated_blocks[curr_block]; // Assign new block
546 curr_block++;
547 }
548 itempos++;
549 }
550
551 if (modifying_this_item) { // We need to log last-accessed block, if it
552 // was modified, but not logged yet.
553 journal_mark_dirty(th, inode->i_sb, bh);
554 }
555
556 if (curr_block < blocks_to_allocate) {
557 // Oh, well need to append to indirect item, or to create indirect item
558 // if there weren't any
559 if (is_indirect_le_ih(ih)) {
560 // Existing indirect item - append. First calculate key for append
561 // position. We do not need to recalculate path as it should
562 // already point to correct place.
563 make_cpu_key(&key, inode,
564 le_key_k_offset(get_inode_item_key_version
565 (inode),
566 &(ih->ih_key)) +
567 op_bytes_number(ih,
568 inode->i_sb->s_blocksize),
569 TYPE_INDIRECT, 3);
570 res =
571 reiserfs_paste_into_item(th, &path, &key, inode,
572 (char *)(allocated_blocks +
573 curr_block),
574 UNFM_P_SIZE *
575 (blocks_to_allocate -
576 curr_block));
577 if (res) {
578 goto error_exit_free_blocks;
579 }
580 } else if (is_statdata_le_ih(ih)) {
581 // Last found item was statdata. That means we need to create indirect item.
582 struct item_head ins_ih; /* itemhead for new item */
583
584 /* create a key for our new item */
585 make_cpu_key(&key, inode, 1, TYPE_INDIRECT, 3); // Position one,
586 // because that's
587 // where first
588 // indirect item
589 // begins
590 /* Create new item head for our new item */
591 make_le_item_head(&ins_ih, &key, key.version, 1,
592 TYPE_INDIRECT,
593 (blocks_to_allocate -
594 curr_block) * UNFM_P_SIZE,
595 0 /* free space */ );
596 /* Find where such item should live in the tree */
597 res = search_item(inode->i_sb, &key, &path);
598 if (res != ITEM_NOT_FOUND) {
599 /* Well, if we have found such item already, or some error
600 occured, we need to warn user and return error */
601 if (res != -ENOSPC) {
602 reiserfs_warning(inode->i_sb,
603 "green-9009: search_by_key (%K) "
604 "returned %d", &key,
605 res);
606 }
607 res = -EIO;
608 goto error_exit_free_blocks;
609 }
610 /* Insert item into the tree with the data as its body */
611 res =
612 reiserfs_insert_item(th, &path, &key, &ins_ih,
613 inode,
614 (char *)(allocated_blocks +
615 curr_block));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 } else {
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700617 reiserfs_panic(inode->i_sb,
618 "green-9010: unexpected item type for key %K\n",
619 &key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700621 }
622 // the caller is responsible for closing the transaction
623 // unless we return an error, they are also responsible for logging
624 // the inode.
625 //
626 pathrelse(&path);
627 /*
628 * cleanup prellocation from previous writes
629 * if this is a partial block write
630 */
631 if (write_bytes & (inode->i_sb->s_blocksize - 1))
632 reiserfs_discard_prealloc(th, inode);
633 reiserfs_write_unlock(inode->i_sb);
634
635 // go through all the pages/buffers and map the buffers to newly allocated
636 // blocks (so that system knows where to write these pages later).
637 curr_block = 0;
638 for (i = 0; i < num_pages; i++) {
639 struct page *page = prepared_pages[i]; //current page
640 struct buffer_head *head = page_buffers(page); // first buffer for a page
641 int block_start, block_end; // in-page offsets for buffers.
642
643 if (!page_buffers(page))
644 reiserfs_panic(inode->i_sb,
645 "green-9005: No buffers for prepared page???");
646
647 /* For each buffer in page */
648 for (bh = head, block_start = 0; bh != head || !block_start;
649 block_start = block_end, bh = bh->b_this_page) {
650 if (!bh)
651 reiserfs_panic(inode->i_sb,
652 "green-9006: Allocated but absent buffer for a page?");
653 block_end = block_start + inode->i_sb->s_blocksize;
654 if (i == 0 && block_end <= from)
655 /* if this buffer is before requested data to map, skip it */
656 continue;
657 if (i == num_pages - 1 && block_start >= to)
658 /* If this buffer is after requested data to map, abort
659 processing of current page */
660 break;
661
662 if (!buffer_mapped(bh)) { // Ok, unmapped buffer, need to map it
663 map_bh(bh, inode->i_sb,
664 le32_to_cpu(allocated_blocks
665 [curr_block]));
666 curr_block++;
667 set_buffer_new(bh);
668 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700672 RFALSE(curr_block > blocks_to_allocate,
673 "green-9007: Used too many blocks? weird");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700675 kfree(allocated_blocks);
676 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678// Need to deal with transaction here.
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700679 error_exit_free_blocks:
680 pathrelse(&path);
681 // free blocks
682 for (i = 0; i < blocks_to_allocate; i++)
683 reiserfs_free_block(th, inode, le32_to_cpu(allocated_blocks[i]),
684 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700686 error_exit:
687 if (th->t_trans_id) {
688 int err;
689 // update any changes we made to blk count
Chris Mason9f037832005-09-13 01:25:17 -0700690 mark_inode_dirty(inode);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700691 err =
692 journal_end(th, inode->i_sb,
693 JOURNAL_PER_BALANCE_CNT * 3 + 1 +
694 2 * REISERFS_QUOTA_TRANS_BLOCKS(inode->i_sb));
695 if (err)
696 res = err;
697 }
698 reiserfs_write_unlock(inode->i_sb);
699 kfree(allocated_blocks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700701 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702}
703
704/* Unlock pages prepared by reiserfs_prepare_file_region_for_write */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700705static void reiserfs_unprepare_pages(struct page **prepared_pages, /* list of locked pages */
706 size_t num_pages /* amount of pages */ )
707{
708 int i; // loop counter
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700710 for (i = 0; i < num_pages; i++) {
711 struct page *page = prepared_pages[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700713 try_to_free_buffers(page);
714 unlock_page(page);
715 page_cache_release(page);
716 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717}
718
719/* This function will copy data from userspace to specified pages within
720 supplied byte range */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700721static int reiserfs_copy_from_user_to_file_region(loff_t pos, /* In-file position */
722 int num_pages, /* Number of pages affected */
723 int write_bytes, /* Amount of bytes to write */
724 struct page **prepared_pages, /* pointer to
725 array to
726 prepared pages
727 */
728 const char __user * buf /* Pointer to user-supplied
729 data */
730 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700732 long page_fault = 0; // status of copy_from_user.
733 int i; // loop counter.
734 int offset; // offset in page
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700736 for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages;
737 i++, offset = 0) {
738 size_t count = min_t(size_t, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page
739 struct page *page = prepared_pages[i]; // Current page we process.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700741 fault_in_pages_readable(buf, count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700743 /* Copy data from userspace to the current page */
744 kmap(page);
745 page_fault = __copy_from_user(page_address(page) + offset, buf, count); // Copy the data.
746 /* Flush processor's dcache for this page */
747 flush_dcache_page(page);
748 kunmap(page);
749 buf += count;
750 write_bytes -= count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700752 if (page_fault)
753 break; // Was there a fault? abort.
754 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700756 return page_fault ? -EFAULT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757}
758
759/* taken fs/buffer.c:__block_commit_write */
760int reiserfs_commit_page(struct inode *inode, struct page *page,
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700761 unsigned from, unsigned to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700763 unsigned block_start, block_end;
764 int partial = 0;
765 unsigned blocksize;
766 struct buffer_head *bh, *head;
767 unsigned long i_size_index = inode->i_size >> PAGE_CACHE_SHIFT;
768 int new;
769 int logit = reiserfs_file_data_log(inode);
770 struct super_block *s = inode->i_sb;
771 int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize;
772 struct reiserfs_transaction_handle th;
773 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700775 th.t_trans_id = 0;
776 blocksize = 1 << inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700778 if (logit) {
779 reiserfs_write_lock(s);
780 ret = journal_begin(&th, s, bh_per_page + 1);
781 if (ret)
782 goto drop_write_lock;
783 reiserfs_update_inode_transaction(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700785 for (bh = head = page_buffers(page), block_start = 0;
786 bh != head || !block_start;
787 block_start = block_end, bh = bh->b_this_page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700789 new = buffer_new(bh);
790 clear_buffer_new(bh);
791 block_end = block_start + blocksize;
792 if (block_end <= from || block_start >= to) {
793 if (!buffer_uptodate(bh))
794 partial = 1;
795 } else {
796 set_buffer_uptodate(bh);
797 if (logit) {
798 reiserfs_prepare_for_journal(s, bh, 1);
799 journal_mark_dirty(&th, s, bh);
800 } else if (!buffer_dirty(bh)) {
801 mark_buffer_dirty(bh);
802 /* do data=ordered on any page past the end
803 * of file and any buffer marked BH_New.
804 */
805 if (reiserfs_data_ordered(inode->i_sb) &&
806 (new || page->index >= i_size_index)) {
807 reiserfs_add_ordered_list(inode, bh);
808 }
809 }
810 }
811 }
812 if (logit) {
813 ret = journal_end(&th, s, bh_per_page + 1);
814 drop_write_lock:
815 reiserfs_write_unlock(s);
816 }
817 /*
818 * If this is a partial write which happened to make all buffers
819 * uptodate then we can optimize away a bogus readpage() for
820 * the next read(). Here we 'discover' whether the page went
821 * uptodate as a result of this (potentially partial) write.
822 */
823 if (!partial)
824 SetPageUptodate(page);
825 return ret;
826}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827
828/* Submit pages for write. This was separated from actual file copying
829 because we might want to allocate block numbers in-between.
830 This function assumes that caller will adjust file size to correct value. */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700831static int reiserfs_submit_file_region_for_write(struct reiserfs_transaction_handle *th, struct inode *inode, loff_t pos, /* Writing position offset */
832 size_t num_pages, /* Number of pages to write */
833 size_t write_bytes, /* number of bytes to write */
834 struct page **prepared_pages /* list of pages */
835 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700837 int status; // return status of block_commit_write.
838 int retval = 0; // Return value we are going to return.
839 int i; // loop counter
840 int offset; // Writing offset in page.
841 int orig_write_bytes = write_bytes;
842 int sd_update = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700844 for (i = 0, offset = (pos & (PAGE_CACHE_SIZE - 1)); i < num_pages;
845 i++, offset = 0) {
846 int count = min_t(int, PAGE_CACHE_SIZE - offset, write_bytes); // How much of bytes to write to this page
847 struct page *page = prepared_pages[i]; // Current page we process.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700849 status =
850 reiserfs_commit_page(inode, page, offset, offset + count);
851 if (status)
852 retval = status; // To not overcomplicate matters We are going to
853 // submit all the pages even if there was error.
854 // we only remember error status to report it on
855 // exit.
856 write_bytes -= count;
857 }
858 /* now that we've gotten all the ordered buffers marked dirty,
859 * we can safely update i_size and close any running transaction
860 */
861 if (pos + orig_write_bytes > inode->i_size) {
862 inode->i_size = pos + orig_write_bytes; // Set new size
863 /* If the file have grown so much that tail packing is no
864 * longer possible, reset "need to pack" flag */
865 if ((have_large_tails(inode->i_sb) &&
866 inode->i_size > i_block_size(inode) * 4) ||
867 (have_small_tails(inode->i_sb) &&
868 inode->i_size > i_block_size(inode)))
869 REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
870 else if ((have_large_tails(inode->i_sb) &&
871 inode->i_size < i_block_size(inode) * 4) ||
872 (have_small_tails(inode->i_sb) &&
873 inode->i_size < i_block_size(inode)))
874 REISERFS_I(inode)->i_flags |= i_pack_on_close_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700876 if (th->t_trans_id) {
877 reiserfs_write_lock(inode->i_sb);
Chris Mason9f037832005-09-13 01:25:17 -0700878 // this sets the proper flags for O_SYNC to trigger a commit
879 mark_inode_dirty(inode);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700880 reiserfs_write_unlock(inode->i_sb);
Hisashi Hifumi73ce5932006-07-10 04:43:56 -0700881 } else {
882 reiserfs_write_lock(inode->i_sb);
883 reiserfs_update_inode_transaction(inode);
Chris Mason9f037832005-09-13 01:25:17 -0700884 mark_inode_dirty(inode);
Hisashi Hifumi73ce5932006-07-10 04:43:56 -0700885 reiserfs_write_unlock(inode->i_sb);
886 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700887
888 sd_update = 1;
889 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 if (th->t_trans_id) {
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700891 reiserfs_write_lock(inode->i_sb);
892 if (!sd_update)
Chris Mason9f037832005-09-13 01:25:17 -0700893 mark_inode_dirty(inode);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700894 status = journal_end(th, th->t_super, th->t_blocks_allocated);
895 if (status)
896 retval = status;
897 reiserfs_write_unlock(inode->i_sb);
898 }
899 th->t_trans_id = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700901 /*
902 * we have to unlock the pages after updating i_size, otherwise
903 * we race with writepage
904 */
905 for (i = 0; i < num_pages; i++) {
906 struct page *page = prepared_pages[i];
907 unlock_page(page);
908 mark_page_accessed(page);
909 page_cache_release(page);
910 }
911 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912}
913
914/* Look if passed writing region is going to touch file's tail
915 (if it is present). And if it is, convert the tail to unformatted node */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700916static int reiserfs_check_for_tail_and_convert(struct inode *inode, /* inode to deal with */
917 loff_t pos, /* Writing position */
918 int write_bytes /* amount of bytes to write */
919 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700921 INITIALIZE_PATH(path); // needed for search_for_position
922 struct cpu_key key; // Key that would represent last touched writing byte.
923 struct item_head *ih; // item header of found block;
924 int res; // Return value of various functions we call.
925 int cont_expand_offset; // We will put offset for generic_cont_expand here
926 // This can be int just because tails are created
927 // only for small files.
928
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929/* this embodies a dependency on a particular tail policy */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700930 if (inode->i_size >= inode->i_sb->s_blocksize * 4) {
931 /* such a big files do not have tails, so we won't bother ourselves
932 to look for tails, simply return */
933 return 0;
934 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700936 reiserfs_write_lock(inode->i_sb);
937 /* find the item containing the last byte to be written, or if
938 * writing past the end of the file then the last item of the
939 * file (and then we check its type). */
940 make_cpu_key(&key, inode, pos + write_bytes + 1, TYPE_ANY,
941 3 /*key length */ );
942 res = search_for_position_by_key(inode->i_sb, &key, &path);
943 if (res == IO_ERROR) {
944 reiserfs_write_unlock(inode->i_sb);
945 return -EIO;
946 }
947 ih = get_ih(&path);
948 res = 0;
949 if (is_direct_le_ih(ih)) {
950 /* Ok, closest item is file tail (tails are stored in "direct"
951 * items), so we need to unpack it. */
952 /* To not overcomplicate matters, we just call generic_cont_expand
953 which will in turn call other stuff and finally will boil down to
954 reiserfs_get_block() that would do necessary conversion. */
955 cont_expand_offset =
956 le_key_k_offset(get_inode_item_key_version(inode),
957 &(ih->ih_key));
958 pathrelse(&path);
959 res = generic_cont_expand(inode, cont_expand_offset);
960 } else
961 pathrelse(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700963 reiserfs_write_unlock(inode->i_sb);
964 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965}
966
967/* This function locks pages starting from @pos for @inode.
968 @num_pages pages are locked and stored in
969 @prepared_pages array. Also buffers are allocated for these pages.
970 First and last page of the region is read if it is overwritten only
971 partially. If last page did not exist before write (file hole or file
972 append), it is zeroed, then.
973 Returns number of unallocated blocks that should be allocated to cover
974 new file data.*/
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700975static int reiserfs_prepare_file_region_for_write(struct inode *inode
976 /* Inode of the file */ ,
977 loff_t pos, /* position in the file */
978 size_t num_pages, /* number of pages to
979 prepare */
980 size_t write_bytes, /* Amount of bytes to be
981 overwritten from
982 @pos */
983 struct page **prepared_pages /* pointer to array
984 where to store
985 prepared pages */
986 )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -0700988 int res = 0; // Return values of different functions we call.
989 unsigned long index = pos >> PAGE_CACHE_SHIFT; // Offset in file in pages.
990 int from = (pos & (PAGE_CACHE_SIZE - 1)); // Writing offset in first page
991 int to = ((pos + write_bytes - 1) & (PAGE_CACHE_SIZE - 1)) + 1;
992 /* offset of last modified byte in last
993 page */
994 struct address_space *mapping = inode->i_mapping; // Pages are mapped here.
995 int i; // Simple counter
996 int blocks = 0; /* Return value (blocks that should be allocated) */
997 struct buffer_head *bh, *head; // Current bufferhead and first bufferhead
998 // of a page.
999 unsigned block_start, block_end; // Starting and ending offsets of current
1000 // buffer in the page.
1001 struct buffer_head *wait[2], **wait_bh = wait; // Buffers for page, if
1002 // Page appeared to be not up
1003 // to date. Note how we have
1004 // at most 2 buffers, this is
1005 // because we at most may
1006 // partially overwrite two
1007 // buffers for one page. One at // the beginning of write area
1008 // and one at the end.
1009 // Everything inthe middle gets // overwritten totally.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001011 struct cpu_key key; // cpu key of item that we are going to deal with
1012 struct item_head *ih = NULL; // pointer to item head that we are going to deal with
1013 struct buffer_head *itembuf = NULL; // Buffer head that contains items that we are going to deal with
1014 INITIALIZE_PATH(path); // path to item, that we are going to deal with.
1015 __le32 *item = NULL; // pointer to item we are going to deal with
1016 int item_pos = -1; /* Position in indirect item */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001018 if (num_pages < 1) {
1019 reiserfs_warning(inode->i_sb,
1020 "green-9001: reiserfs_prepare_file_region_for_write "
1021 "called with zero number of pages to process");
1022 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 }
1024
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001025 /* We have 2 loops for pages. In first loop we grab and lock the pages, so
1026 that nobody would touch these until we release the pages. Then
1027 we'd start to deal with mapping buffers to blocks. */
1028 for (i = 0; i < num_pages; i++) {
1029 prepared_pages[i] = grab_cache_page(mapping, index + i); // locks the page
1030 if (!prepared_pages[i]) {
1031 res = -ENOMEM;
1032 goto failed_page_grabbing;
1033 }
1034 if (!page_has_buffers(prepared_pages[i]))
1035 create_empty_buffers(prepared_pages[i],
1036 inode->i_sb->s_blocksize, 0);
1037 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001039 /* Let's count amount of blocks for a case where all the blocks
1040 overwritten are new (we will substract already allocated blocks later) */
1041 if (num_pages > 2)
1042 /* These are full-overwritten pages so we count all the blocks in
1043 these pages are counted as needed to be allocated */
1044 blocks =
1045 (num_pages - 2) << (PAGE_CACHE_SHIFT - inode->i_blkbits);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001047 /* count blocks needed for first page (possibly partially written) */
1048 blocks += ((PAGE_CACHE_SIZE - from) >> inode->i_blkbits) + !!(from & (inode->i_sb->s_blocksize - 1)); /* roundup */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001050 /* Now we account for last page. If last page == first page (we
1051 overwrite only one page), we substract all the blocks past the
1052 last writing position in a page out of already calculated number
1053 of blocks */
1054 blocks += ((num_pages > 1) << (PAGE_CACHE_SHIFT - inode->i_blkbits)) -
1055 ((PAGE_CACHE_SIZE - to) >> inode->i_blkbits);
1056 /* Note how we do not roundup here since partial blocks still
1057 should be allocated */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001059 /* Now if all the write area lies past the file end, no point in
1060 maping blocks, since there is none, so we just zero out remaining
1061 parts of first and last pages in write area (if needed) */
1062 if ((pos & ~((loff_t) PAGE_CACHE_SIZE - 1)) > inode->i_size) {
1063 if (from != 0) { /* First page needs to be partially zeroed */
1064 char *kaddr = kmap_atomic(prepared_pages[0], KM_USER0);
1065 memset(kaddr, 0, from);
1066 kunmap_atomic(kaddr, KM_USER0);
Alexey Dobriyande21c572006-12-06 20:38:02 -08001067 flush_dcache_page(prepared_pages[0]);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001068 }
1069 if (to != PAGE_CACHE_SIZE) { /* Last page needs to be partially zeroed */
1070 char *kaddr =
1071 kmap_atomic(prepared_pages[num_pages - 1],
1072 KM_USER0);
1073 memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
1074 kunmap_atomic(kaddr, KM_USER0);
Alexey Dobriyande21c572006-12-06 20:38:02 -08001075 flush_dcache_page(prepared_pages[num_pages - 1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 }
1077
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001078 /* Since all blocks are new - use already calculated value */
1079 return blocks;
1080 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001082 /* Well, since we write somewhere into the middle of a file, there is
1083 possibility we are writing over some already allocated blocks, so
1084 let's map these blocks and substract number of such blocks out of blocks
1085 we need to allocate (calculated above) */
1086 /* Mask write position to start on blocksize, we do it out of the
1087 loop for performance reasons */
1088 pos &= ~((loff_t) inode->i_sb->s_blocksize - 1);
1089 /* Set cpu key to the starting position in a file (on left block boundary) */
1090 make_cpu_key(&key, inode,
1091 1 + ((pos) & ~((loff_t) inode->i_sb->s_blocksize - 1)),
1092 TYPE_ANY, 3 /*key length */ );
1093
1094 reiserfs_write_lock(inode->i_sb); // We need that for at least search_by_key()
1095 for (i = 0; i < num_pages; i++) {
1096
1097 head = page_buffers(prepared_pages[i]);
1098 /* For each buffer in the page */
1099 for (bh = head, block_start = 0; bh != head || !block_start;
1100 block_start = block_end, bh = bh->b_this_page) {
1101 if (!bh)
1102 reiserfs_panic(inode->i_sb,
1103 "green-9002: Allocated but absent buffer for a page?");
1104 /* Find where this buffer ends */
1105 block_end = block_start + inode->i_sb->s_blocksize;
1106 if (i == 0 && block_end <= from)
1107 /* if this buffer is before requested data to map, skip it */
1108 continue;
1109
1110 if (i == num_pages - 1 && block_start >= to) {
1111 /* If this buffer is after requested data to map, abort
1112 processing of current page */
1113 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 }
1115
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001116 if (buffer_mapped(bh) && bh->b_blocknr != 0) {
1117 /* This is optimisation for a case where buffer is mapped
1118 and have blocknumber assigned. In case significant amount
1119 of such buffers are present, we may avoid some amount
1120 of search_by_key calls.
1121 Probably it would be possible to move parts of this code
1122 out of BKL, but I afraid that would overcomplicate code
1123 without any noticeable benefit.
1124 */
1125 item_pos++;
1126 /* Update the key */
1127 set_cpu_key_k_offset(&key,
1128 cpu_key_k_offset(&key) +
1129 inode->i_sb->s_blocksize);
1130 blocks--; // Decrease the amount of blocks that need to be
1131 // allocated
1132 continue; // Go to the next buffer
1133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001135 if (!itembuf || /* if first iteration */
1136 item_pos >= ih_item_len(ih) / UNFM_P_SIZE) { /* or if we progressed past the
1137 current unformatted_item */
1138 /* Try to find next item */
1139 res =
1140 search_for_position_by_key(inode->i_sb,
1141 &key, &path);
1142 /* Abort if no more items */
1143 if (res != POSITION_FOUND) {
1144 /* make sure later loops don't use this item */
1145 itembuf = NULL;
1146 item = NULL;
1147 break;
1148 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001150 /* Update information about current indirect item */
1151 itembuf = get_last_bh(&path);
1152 ih = get_ih(&path);
1153 item = get_item(&path);
1154 item_pos = path.pos_in_item;
1155
1156 RFALSE(!is_indirect_le_ih(ih),
1157 "green-9003: indirect item expected");
1158 }
1159
1160 /* See if there is some block associated with the file
1161 at that position, map the buffer to this block */
1162 if (get_block_num(item, item_pos)) {
1163 map_bh(bh, inode->i_sb,
1164 get_block_num(item, item_pos));
1165 blocks--; // Decrease the amount of blocks that need to be
1166 // allocated
1167 }
1168 item_pos++;
1169 /* Update the key */
1170 set_cpu_key_k_offset(&key,
1171 cpu_key_k_offset(&key) +
1172 inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 }
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001175 pathrelse(&path); // Free the path
1176 reiserfs_write_unlock(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177
1178 /* Now zero out unmappend buffers for the first and last pages of
1179 write area or issue read requests if page is mapped. */
1180 /* First page, see if it is not uptodate */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001181 if (!PageUptodate(prepared_pages[0])) {
1182 head = page_buffers(prepared_pages[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001184 /* For each buffer in page */
1185 for (bh = head, block_start = 0; bh != head || !block_start;
1186 block_start = block_end, bh = bh->b_this_page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001188 if (!bh)
1189 reiserfs_panic(inode->i_sb,
1190 "green-9002: Allocated but absent buffer for a page?");
1191 /* Find where this buffer ends */
1192 block_end = block_start + inode->i_sb->s_blocksize;
1193 if (block_end <= from)
1194 /* if this buffer is before requested data to map, skip it */
1195 continue;
1196 if (block_start < from) { /* Aha, our partial buffer */
1197 if (buffer_mapped(bh)) { /* If it is mapped, we need to
1198 issue READ request for it to
1199 not loose data */
1200 ll_rw_block(READ, 1, &bh);
1201 *wait_bh++ = bh;
1202 } else { /* Not mapped, zero it */
1203 char *kaddr =
1204 kmap_atomic(prepared_pages[0],
1205 KM_USER0);
1206 memset(kaddr + block_start, 0,
1207 from - block_start);
1208 kunmap_atomic(kaddr, KM_USER0);
Alexey Dobriyande21c572006-12-06 20:38:02 -08001209 flush_dcache_page(prepared_pages[0]);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001210 set_buffer_uptodate(bh);
1211 }
1212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 }
1215
1216 /* Last page, see if it is not uptodate, or if the last page is past the end of the file. */
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001217 if (!PageUptodate(prepared_pages[num_pages - 1]) ||
1218 ((pos + write_bytes) >> PAGE_CACHE_SHIFT) >
1219 (inode->i_size >> PAGE_CACHE_SHIFT)) {
1220 head = page_buffers(prepared_pages[num_pages - 1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001222 /* for each buffer in page */
1223 for (bh = head, block_start = 0; bh != head || !block_start;
1224 block_start = block_end, bh = bh->b_this_page) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001226 if (!bh)
1227 reiserfs_panic(inode->i_sb,
1228 "green-9002: Allocated but absent buffer for a page?");
1229 /* Find where this buffer ends */
1230 block_end = block_start + inode->i_sb->s_blocksize;
1231 if (block_start >= to)
1232 /* if this buffer is after requested data to map, skip it */
1233 break;
1234 if (block_end > to) { /* Aha, our partial buffer */
1235 if (buffer_mapped(bh)) { /* If it is mapped, we need to
1236 issue READ request for it to
1237 not loose data */
1238 ll_rw_block(READ, 1, &bh);
1239 *wait_bh++ = bh;
1240 } else { /* Not mapped, zero it */
1241 char *kaddr =
1242 kmap_atomic(prepared_pages
1243 [num_pages - 1],
1244 KM_USER0);
1245 memset(kaddr + to, 0, block_end - to);
1246 kunmap_atomic(kaddr, KM_USER0);
Alexey Dobriyande21c572006-12-06 20:38:02 -08001247 flush_dcache_page(prepared_pages[num_pages - 1]);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001248 set_buffer_uptodate(bh);
1249 }
1250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 }
1253
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001254 /* Wait for read requests we made to happen, if necessary */
1255 while (wait_bh > wait) {
1256 wait_on_buffer(*--wait_bh);
1257 if (!buffer_uptodate(*wait_bh)) {
1258 res = -EIO;
1259 goto failed_read;
1260 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001263 return blocks;
1264 failed_page_grabbing:
1265 num_pages = i;
1266 failed_read:
1267 reiserfs_unprepare_pages(prepared_pages, num_pages);
1268 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269}
1270
1271/* Write @count bytes at position @ppos in a file indicated by @file
1272 from the buffer @buf.
1273
1274 generic_file_write() is only appropriate for filesystems that are not seeking to optimize performance and want
1275 something simple that works. It is not for serious use by general purpose filesystems, excepting the one that it was
1276 written for (ext2/3). This is for several reasons:
1277
1278 * It has no understanding of any filesystem specific optimizations.
1279
1280 * It enters the filesystem repeatedly for each page that is written.
1281
1282 * It depends on reiserfs_get_block() function which if implemented by reiserfs performs costly search_by_key
1283 * operation for each page it is supplied with. By contrast reiserfs_file_write() feeds as much as possible at a time
1284 * to reiserfs which allows for fewer tree traversals.
1285
1286 * Each indirect pointer insertion takes a lot of cpu, because it involves memory moves inside of blocks.
1287
1288 * Asking the block allocation code for blocks one at a time is slightly less efficient.
1289
1290 All of these reasons for not using only generic file write were understood back when reiserfs was first miscoded to
1291 use it, but we were in a hurry to make code freeze, and so it couldn't be revised then. This new code should make
1292 things right finally.
1293
1294 Future Features: providing search_by_key with hints.
1295
1296*/
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001297static ssize_t reiserfs_file_write(struct file *file, /* the file we are going to write into */
1298 const char __user * buf, /* pointer to user supplied data
1299 (in userspace) */
1300 size_t count, /* amount of bytes to write */
1301 loff_t * ppos /* pointer to position in file that we start writing at. Should be updated to
1302 * new current position before returning. */
1303 )
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304{
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001305 size_t already_written = 0; // Number of bytes already written to the file.
1306 loff_t pos; // Current position in the file.
1307 ssize_t res; // return value of various functions that we call.
1308 int err = 0;
Josef Sipek1fc5adb2006-12-08 02:37:33 -08001309 struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to.
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001310 /* To simplify coding at this time, we store
1311 locked pages in array for now */
1312 struct page *prepared_pages[REISERFS_WRITE_PAGES_AT_A_TIME];
1313 struct reiserfs_transaction_handle th;
1314 th.t_trans_id = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315
Jeff Mahoneyfa385be2006-02-01 03:06:51 -08001316 /* If a filesystem is converted from 3.5 to 3.6, we'll have v3.5 items
1317 * lying around (most of the disk, in fact). Despite the filesystem
1318 * now being a v3.6 format, the old items still can't support large
1319 * file sizes. Catch this case here, as the rest of the VFS layer is
1320 * oblivious to the different limitations between old and new items.
1321 * reiserfs_setattr catches this for truncates. This chunk is lifted
1322 * from generic_write_checks. */
1323 if (get_inode_item_key_version (inode) == KEY_FORMAT_3_5 &&
1324 *ppos + count > MAX_NON_LFS) {
1325 if (*ppos >= MAX_NON_LFS) {
1326 send_sig(SIGXFSZ, current, 0);
1327 return -EFBIG;
1328 }
1329 if (count > MAX_NON_LFS - (unsigned long)*ppos)
1330 count = MAX_NON_LFS - (unsigned long)*ppos;
1331 }
1332
Vladimir V. Savelievc5574762006-12-06 20:39:12 -08001333 if (file->f_flags & O_DIRECT)
1334 return do_sync_write(file, buf, count, ppos);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001336 if (unlikely((ssize_t) count < 0))
1337 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001339 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
1340 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001342 mutex_lock(&inode->i_mutex); // locks the entire file for just us
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001344 pos = *ppos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001346 /* Check if we can write to specified region of file, file
1347 is not overly big and this kind of stuff. Adjust pos and
1348 count, if needed */
1349 res = generic_write_checks(file, &pos, &count, 0);
1350 if (res)
1351 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001353 if (count == 0)
1354 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355
Josef Sipek1fc5adb2006-12-08 02:37:33 -08001356 res = remove_suid(file->f_path.dentry);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001357 if (res)
1358 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359
Christoph Hellwig870f4812006-01-09 20:52:01 -08001360 file_update_time(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001362 // Ok, we are done with all the checks.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001364 // Now we should start real work
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001366 /* If we are going to write past the file's packed tail or if we are going
1367 to overwrite part of the tail, we need that tail to be converted into
1368 unformatted node */
1369 res = reiserfs_check_for_tail_and_convert(inode, pos, count);
1370 if (res)
1371 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001373 while (count > 0) {
1374 /* This is the main loop in which we running until some error occures
1375 or until we write all of the data. */
1376 size_t num_pages; /* amount of pages we are going to write this iteration */
1377 size_t write_bytes; /* amount of bytes to write during this iteration */
1378 size_t blocks_to_allocate; /* how much blocks we need to allocate for this iteration */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001380 /* (pos & (PAGE_CACHE_SIZE-1)) is an idiom for offset into a page of pos */
1381 num_pages = !!((pos + count) & (PAGE_CACHE_SIZE - 1)) + /* round up partial
1382 pages */
1383 ((count +
1384 (pos & (PAGE_CACHE_SIZE - 1))) >> PAGE_CACHE_SHIFT);
1385 /* convert size to amount of
1386 pages */
1387 reiserfs_write_lock(inode->i_sb);
1388 if (num_pages > REISERFS_WRITE_PAGES_AT_A_TIME
1389 || num_pages > reiserfs_can_fit_pages(inode->i_sb)) {
1390 /* If we were asked to write more data than we want to or if there
1391 is not that much space, then we shorten amount of data to write
1392 for this iteration. */
1393 num_pages =
1394 min_t(size_t, REISERFS_WRITE_PAGES_AT_A_TIME,
1395 reiserfs_can_fit_pages(inode->i_sb));
1396 /* Also we should not forget to set size in bytes accordingly */
1397 write_bytes = (num_pages << PAGE_CACHE_SHIFT) -
1398 (pos & (PAGE_CACHE_SIZE - 1));
1399 /* If position is not on the
1400 start of the page, we need
1401 to substract the offset
1402 within page */
1403 } else
1404 write_bytes = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001406 /* reserve the blocks to be allocated later, so that later on
1407 we still have the space to write the blocks to */
1408 reiserfs_claim_blocks_to_be_allocated(inode->i_sb,
1409 num_pages <<
1410 (PAGE_CACHE_SHIFT -
1411 inode->i_blkbits));
1412 reiserfs_write_unlock(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001414 if (!num_pages) { /* If we do not have enough space even for a single page... */
1415 if (pos >
1416 inode->i_size + inode->i_sb->s_blocksize -
1417 (pos & (inode->i_sb->s_blocksize - 1))) {
1418 res = -ENOSPC;
1419 break; // In case we are writing past the end of the last file block, break.
1420 }
1421 // Otherwise we are possibly overwriting the file, so
1422 // let's set write size to be equal or less than blocksize.
1423 // This way we get it correctly for file holes.
1424 // But overwriting files on absolutelly full volumes would not
1425 // be very efficient. Well, people are not supposed to fill
1426 // 100% of disk space anyway.
1427 write_bytes =
1428 min_t(size_t, count,
1429 inode->i_sb->s_blocksize -
1430 (pos & (inode->i_sb->s_blocksize - 1)));
1431 num_pages = 1;
1432 // No blocks were claimed before, so do it now.
1433 reiserfs_claim_blocks_to_be_allocated(inode->i_sb,
1434 1 <<
1435 (PAGE_CACHE_SHIFT
1436 -
1437 inode->
1438 i_blkbits));
1439 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001441 /* Prepare for writing into the region, read in all the
1442 partially overwritten pages, if needed. And lock the pages,
1443 so that nobody else can access these until we are done.
1444 We get number of actual blocks needed as a result. */
Vladimir V. Savelievc499ec22006-03-02 02:54:39 -08001445 res = reiserfs_prepare_file_region_for_write(inode, pos,
1446 num_pages,
1447 write_bytes,
1448 prepared_pages);
1449 if (res < 0) {
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001450 reiserfs_release_claimed_blocks(inode->i_sb,
1451 num_pages <<
1452 (PAGE_CACHE_SHIFT -
1453 inode->i_blkbits));
1454 break;
1455 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456
Vladimir V. Savelievc499ec22006-03-02 02:54:39 -08001457 blocks_to_allocate = res;
1458
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001459 /* First we correct our estimate of how many blocks we need */
1460 reiserfs_release_claimed_blocks(inode->i_sb,
1461 (num_pages <<
1462 (PAGE_CACHE_SHIFT -
1463 inode->i_sb->
1464 s_blocksize_bits)) -
1465 blocks_to_allocate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001467 if (blocks_to_allocate > 0) { /*We only allocate blocks if we need to */
1468 /* Fill in all the possible holes and append the file if needed */
1469 res =
1470 reiserfs_allocate_blocks_for_region(&th, inode, pos,
1471 num_pages,
1472 write_bytes,
1473 prepared_pages,
1474 blocks_to_allocate);
1475 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001477 /* well, we have allocated the blocks, so it is time to free
1478 the reservation we made earlier. */
1479 reiserfs_release_claimed_blocks(inode->i_sb,
1480 blocks_to_allocate);
1481 if (res) {
1482 reiserfs_unprepare_pages(prepared_pages, num_pages);
1483 break;
1484 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485
1486/* NOTE that allocating blocks and filling blocks can be done in reverse order
1487 and probably we would do that just to get rid of garbage in files after a
1488 crash */
1489
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001490 /* Copy data from user-supplied buffer to file's pages */
1491 res =
1492 reiserfs_copy_from_user_to_file_region(pos, num_pages,
1493 write_bytes,
1494 prepared_pages, buf);
1495 if (res) {
1496 reiserfs_unprepare_pages(prepared_pages, num_pages);
1497 break;
1498 }
1499
1500 /* Send the pages to disk and unlock them. */
1501 res =
1502 reiserfs_submit_file_region_for_write(&th, inode, pos,
1503 num_pages,
1504 write_bytes,
1505 prepared_pages);
1506 if (res)
1507 break;
1508
1509 already_written += write_bytes;
1510 buf += write_bytes;
1511 *ppos = pos += write_bytes;
1512 count -= write_bytes;
Alexander Zarochentsev59308602006-03-25 03:07:16 -08001513 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514 }
1515
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001516 /* this is only true on error */
1517 if (th.t_trans_id) {
1518 reiserfs_write_lock(inode->i_sb);
1519 err = journal_end(&th, th.t_super, th.t_blocks_allocated);
1520 reiserfs_write_unlock(inode->i_sb);
1521 if (err) {
1522 res = err;
1523 goto out;
1524 }
1525 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526
Jeff Mahoney619d5d82006-03-25 03:07:00 -08001527 if (likely(res >= 0) &&
1528 (unlikely((file->f_flags & O_SYNC) || IS_SYNC(inode))))
1529 res = generic_osync_inode(inode, file->f_mapping,
1530 OSYNC_METADATA | OSYNC_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001532 mutex_unlock(&inode->i_mutex);
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001533 reiserfs_async_progress_wait(inode->i_sb);
1534 return (already_written != 0) ? already_written : res;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001536 out:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001537 mutex_unlock(&inode->i_mutex); // unlock the file on exit.
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001538 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001539}
1540
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -08001541const struct file_operations reiserfs_file_operations = {
Badari Pulavarty027445c2006-09-30 23:28:46 -07001542 .read = do_sync_read,
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001543 .write = reiserfs_file_write,
1544 .ioctl = reiserfs_ioctl,
David Howells52b499c2006-08-29 19:06:18 +01001545#ifdef CONFIG_COMPAT
1546 .compat_ioctl = reiserfs_compat_ioctl,
1547#endif
Vladimir Savelievde145692007-01-22 20:40:46 -08001548 .mmap = reiserfs_file_mmap,
Jeff Mahoney5a2618e2006-09-30 23:28:44 -07001549 .open = generic_file_open,
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001550 .release = reiserfs_file_release,
1551 .fsync = reiserfs_sync_file,
1552 .sendfile = generic_file_sendfile,
1553 .aio_read = generic_file_aio_read,
Alexey Dobriyan9637f282006-06-26 00:24:57 -07001554 .aio_write = generic_file_aio_write,
Jens Axboe5274f052006-03-30 15:15:30 +02001555 .splice_read = generic_file_splice_read,
1556 .splice_write = generic_file_splice_write,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001557};
1558
Linus Torvaldsbd4c6252005-07-12 20:21:28 -07001559struct inode_operations reiserfs_file_inode_operations = {
1560 .truncate = reiserfs_vfs_truncate_file,
1561 .setattr = reiserfs_setattr,
1562 .setxattr = reiserfs_setxattr,
1563 .getxattr = reiserfs_getxattr,
1564 .listxattr = reiserfs_listxattr,
1565 .removexattr = reiserfs_removexattr,
1566 .permission = reiserfs_permission,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567};