1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/mm.h>
16 #include <linux/pagemap.h>
17 #include <linux/writeback.h>
18 #include <linux/swap.h>
19 #include <linux/delay.h>
20 #include <linux/bio.h>
21 #include <linux/gfs2_ondisk.h>
22 #include <linux/lm_interface.h>
23
24 #include "gfs2.h"
25 #include "incore.h"
26 #include "glock.h"
27 #include "glops.h"
28 #include "inode.h"
29 #include "log.h"
30 #include "lops.h"
31 #include "meta_io.h"
32 #include "rgrp.h"
33 #include "trans.h"
34 #include "util.h"
35 #include "ops_address.h"
36
37 static int aspace_get_block(struct inode *inode, sector_t lblock,
38 struct buffer_head *bh_result, int create)
39 {
40 gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
41 return -EOPNOTSUPP;
42 }
43
44 static int gfs2_aspace_writepage(struct page *page,
45 struct writeback_control *wbc)
46 {
47 return block_write_full_page(page, aspace_get_block, wbc);
48 }
49
50 static const struct address_space_operations aspace_aops = {
51 .writepage = gfs2_aspace_writepage,
52 .releasepage = gfs2_releasepage,
53 .sync_page = block_sync_page,
54 };
55
56 /**
57 * gfs2_aspace_get - Create and initialize a struct inode structure
58 * @sdp: the filesystem the aspace is in
59 *
60 * Right now a struct inode is just a struct inode. Maybe Linux
61 * will supply a more lightweight address space construct (that works)
62 * in the future.
63 *
64 * Make sure pages/buffers in this aspace aren't in high memory.
65 *
66 * Returns: the aspace
67 */
68
69 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
70 {
71 struct inode *aspace;
72
73 aspace = new_inode(sdp->sd_vfs);
74 if (aspace) {
75 mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
76 aspace->i_mapping->a_ops = &aspace_aops;
77 aspace->i_size = ~0ULL;
78 aspace->i_private = NULL;
79 insert_inode_hash(aspace);
80 }
81 return aspace;
82 }
83
84 void gfs2_aspace_put(struct inode *aspace)
85 {
86 remove_inode_hash(aspace);
87 iput(aspace);
88 }
89
90 /**
91 * gfs2_meta_inval - Invalidate all buffers associated with a glock
92 * @gl: the glock
93 *
94 */
95
96 void gfs2_meta_inval(struct gfs2_glock *gl)
97 {
98 struct gfs2_sbd *sdp = gl->gl_sbd;
99 struct inode *aspace = gl->gl_aspace;
100 struct address_space *mapping = gl->gl_aspace->i_mapping;
101
102 gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
103
104 atomic_inc(&aspace->i_writecount);
105 truncate_inode_pages(mapping, 0);
106 atomic_dec(&aspace->i_writecount);
107
108 gfs2_assert_withdraw(sdp, !mapping->nrpages);
109 }
110
111 /**
112 * gfs2_meta_sync - Sync all buffers associated with a glock
113 * @gl: The glock
114 *
115 */
116
117 void gfs2_meta_sync(struct gfs2_glock *gl)
118 {
119 struct address_space *mapping = gl->gl_aspace->i_mapping;
120 int error;
121
122 filemap_fdatawrite(mapping);
123 error = filemap_fdatawait(mapping);
124
125 if (error)
126 gfs2_io_error(gl->gl_sbd);
127 }
128
129 /**
130 * getbuf - Get a buffer with a given address space
131 * @gl: the glock
132 * @blkno: the block number (filesystem scope)
133 * @create: 1 if the buffer should be created
134 *
135 * Returns: the buffer
136 */
137
138 static struct buffer_head *getbuf(struct gfs2_glock *gl, u64 blkno, int create)
139 {
140 struct address_space *mapping = gl->gl_aspace->i_mapping;
141 struct gfs2_sbd *sdp = gl->gl_sbd;
142 struct page *page;
143 struct buffer_head *bh;
144 unsigned int shift;
145 unsigned long index;
146 unsigned int bufnum;
147
148 shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
149 index = blkno >> shift; /* convert block to page */
150 bufnum = blkno - (index << shift); /* block buf index within page */
151
152 if (create) {
153 for (;;) {
154 page = grab_cache_page(mapping, index);
155 if (page)
156 break;
157 yield();
158 }
159 } else {
160 page = find_lock_page(mapping, index);
161 if (!page)
162 return NULL;
163 }
164
165 if (!page_has_buffers(page))
166 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
167
168 /* Locate header for our buffer within our page */
169 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
170 /* Do nothing */;
171 get_bh(bh);
172
173 if (!buffer_mapped(bh))
174 map_bh(bh, sdp->sd_vfs, blkno);
175
176 unlock_page(page);
177 mark_page_accessed(page);
178 page_cache_release(page);
179
180 return bh;
181 }
182
183 static void meta_prep_new(struct buffer_head *bh)
184 {
185 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
186
187 lock_buffer(bh);
188 clear_buffer_dirty(bh);
189 set_buffer_uptodate(bh);
190 unlock_buffer(bh);
191
192 mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
193 }
194
195 /**
196 * gfs2_meta_new - Get a block
197 * @gl: The glock associated with this block
198 * @blkno: The block number
199 *
200 * Returns: The buffer
201 */
202
203 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
204 {
205 struct buffer_head *bh;
206 bh = getbuf(gl, blkno, CREATE);
207 meta_prep_new(bh);
208 return bh;
209 }
210
211 /**
212 * gfs2_meta_read - Read a block from disk
213 * @gl: The glock covering the block
214 * @blkno: The block number
215 * @flags: flags
216 * @bhp: the place where the buffer is returned (NULL on failure)
217 *
218 * Returns: errno
219 */
220
221 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
222 struct buffer_head **bhp)
223 {
224 *bhp = getbuf(gl, blkno, CREATE);
225 if (!buffer_uptodate(*bhp)) {
226 ll_rw_block(READ_META, 1, bhp);
227 if (flags & DIO_WAIT) {
228 int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
229 if (error) {
230 brelse(*bhp);
231 return error;
232 }
233 }
234 }
235
236 return 0;
237 }
238
239 /**
240 * gfs2_meta_wait - Reread a block from disk
241 * @sdp: the filesystem
242 * @bh: The block to wait for
243 *
244 * Returns: errno
245 */
246
247 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
248 {
249 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
250 return -EIO;
251
252 wait_on_buffer(bh);
253
254 if (!buffer_uptodate(bh)) {
255 struct gfs2_trans *tr = current->journal_info;
256 if (tr && tr->tr_touched)
257 gfs2_io_error_bh(sdp, bh);
258 return -EIO;
259 }
260 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
261 return -EIO;
262
263 return 0;
264 }
265
266 /**
267 * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
268 * @gl: the glock the buffer belongs to
269 * @bh: The buffer to be attached to
270 * @meta: Flag to indicate whether its metadata or not
271 */
272
273 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
274 int meta)
275 {
276 struct gfs2_bufdata *bd;
277
278 if (meta)
279 lock_page(bh->b_page);
280
281 if (bh->b_private) {
282 if (meta)
283 unlock_page(bh->b_page);
284 return;
285 }
286
287 bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
288 bd->bd_bh = bh;
289 bd->bd_gl = gl;
290
291 INIT_LIST_HEAD(&bd->bd_list_tr);
292 if (meta)
293 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
294 else
295 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
296 bh->b_private = bd;
297
298 if (meta)
299 unlock_page(bh->b_page);
300 }
301
302 void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
303 {
304 struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
305 struct gfs2_bufdata *bd = bh->b_private;
306 if (test_clear_buffer_pinned(bh)) {
307 list_del_init(&bd->bd_le.le_list);
308 if (meta) {
309 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
310 sdp->sd_log_num_buf--;
311 tr->tr_num_buf_rm++;
312 } else {
313 gfs2_assert_warn(sdp, sdp->sd_log_num_databuf);
314 sdp->sd_log_num_databuf--;
315 tr->tr_num_databuf_rm++;
316 }
317 tr->tr_touched = 1;
318 brelse(bh);
319 }
320 if (bd) {
321 if (bd->bd_ail) {
322 gfs2_remove_from_ail(bd);
323 bh->b_private = NULL;
324 bd->bd_bh = NULL;
325 bd->bd_blkno = bh->b_blocknr;
326 gfs2_trans_add_revoke(sdp, bd);
327 }
328 }
329 clear_buffer_dirty(bh);
330 clear_buffer_uptodate(bh);
331 }
332
333 /**
334 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
335 * @ip: the inode who owns the buffers
336 * @bstart: the first buffer in the run
337 * @blen: the number of buffers in the run
338 *
339 */
340
341 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
342 {
343 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
344 struct buffer_head *bh;
345
346 while (blen) {
347 bh = getbuf(ip->i_gl, bstart, NO_CREATE);
348 if (bh) {
349 lock_buffer(bh);
350 gfs2_log_lock(sdp);
351 gfs2_remove_from_journal(bh, current->journal_info, 1);
352 gfs2_log_unlock(sdp);
353 unlock_buffer(bh);
354 brelse(bh);
355 }
356
357 bstart++;
358 blen--;
359 }
360 }
361
362 /**
363 * gfs2_meta_indirect_buffer - Get a metadata buffer
364 * @ip: The GFS2 inode
365 * @height: The level of this buf in the metadata (indir addr) tree (if any)
366 * @num: The block number (device relative) of the buffer
367 * @new: Non-zero if we may create a new buffer
368 * @bhp: the buffer is returned here
369 *
370 * Returns: errno
371 */
372
373 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
374 int new, struct buffer_head **bhp)
375 {
376 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
377 struct gfs2_glock *gl = ip->i_gl;
378 struct buffer_head *bh;
379 int ret = 0;
380
381 if (new) {
382 BUG_ON(height == 0);
383 bh = gfs2_meta_new(gl, num);
384 gfs2_trans_add_bh(ip->i_gl, bh, 1);
385 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
386 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
387 } else {
388 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
389 ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh);
390 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) {
391 brelse(bh);
392 ret = -EIO;
393 }
394 }
395 *bhp = bh;
396 return ret;
397 }
398
399 /**
400 * gfs2_meta_ra - start readahead on an extent of a file
401 * @gl: the glock the blocks belong to
402 * @dblock: the starting disk block
403 * @extlen: the number of blocks in the extent
404 *
405 * returns: the first buffer in the extent
406 */
407
408 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
409 {
410 struct gfs2_sbd *sdp = gl->gl_sbd;
411 struct buffer_head *first_bh, *bh;
412 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
413 sdp->sd_sb.sb_bsize_shift;
414
415 BUG_ON(!extlen);
416
417 if (max_ra < 1)
418 max_ra = 1;
419 if (extlen > max_ra)
420 extlen = max_ra;
421
422 first_bh = getbuf(gl, dblock, CREATE);
423
424 if (buffer_uptodate(first_bh))
425 goto out;
426 if (!buffer_locked(first_bh))
427 ll_rw_block(READ_META, 1, &first_bh);
428
429 dblock++;
430 extlen--;
431
432 while (extlen) {
433 bh = getbuf(gl, dblock, CREATE);
434
435 if (!buffer_uptodate(bh) && !buffer_locked(bh))
436 ll_rw_block(READA, 1, &bh);
437 brelse(bh);
438 dblock++;
439 extlen--;
440 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
441 goto out;
442 }
443
444 wait_on_buffer(first_bh);
445 out:
446 return first_bh;
447 }
448
449
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