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