1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2008 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 struct gfs2_inode *ip; 73 74 aspace = new_inode(sdp->sd_vfs); 75 if (aspace) { 76 mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS); 77 aspace->i_mapping->a_ops = &aspace_aops; 78 aspace->i_size = ~0ULL; 79 ip = GFS2_I(aspace); 80 clear_bit(GIF_USER, &ip->i_flags); 81 insert_inode_hash(aspace); 82 } 83 return aspace; 84 } 85 86 void gfs2_aspace_put(struct inode *aspace) 87 { 88 remove_inode_hash(aspace); 89 iput(aspace); 90 } 91 92 /** 93 * gfs2_meta_inval - Invalidate all buffers associated with a glock 94 * @gl: the glock 95 * 96 */ 97 98 void gfs2_meta_inval(struct gfs2_glock *gl) 99 { 100 struct gfs2_sbd *sdp = gl->gl_sbd; 101 struct inode *aspace = gl->gl_aspace; 102 struct address_space *mapping = gl->gl_aspace->i_mapping; 103 104 gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count)); 105 106 atomic_inc(&aspace->i_writecount); 107 truncate_inode_pages(mapping, 0); 108 atomic_dec(&aspace->i_writecount); 109 110 gfs2_assert_withdraw(sdp, !mapping->nrpages); 111 } 112 113 /** 114 * gfs2_meta_sync - Sync all buffers associated with a glock 115 * @gl: The glock 116 * 117 */ 118 119 void gfs2_meta_sync(struct gfs2_glock *gl) 120 { 121 struct address_space *mapping = gl->gl_aspace->i_mapping; 122 int error; 123 124 filemap_fdatawrite(mapping); 125 error = filemap_fdatawait(mapping); 126 127 if (error) 128 gfs2_io_error(gl->gl_sbd); 129 } 130 131 /** 132 * gfs2_getbuf - Get a buffer with a given address space 133 * @gl: the glock 134 * @blkno: the block number (filesystem scope) 135 * @create: 1 if the buffer should be created 136 * 137 * Returns: the buffer 138 */ 139 140 struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create) 141 { 142 struct address_space *mapping = gl->gl_aspace->i_mapping; 143 struct gfs2_sbd *sdp = gl->gl_sbd; 144 struct page *page; 145 struct buffer_head *bh; 146 unsigned int shift; 147 unsigned long index; 148 unsigned int bufnum; 149 150 shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift; 151 index = blkno >> shift; /* convert block to page */ 152 bufnum = blkno - (index << shift); /* block buf index within page */ 153 154 if (create) { 155 for (;;) { 156 page = grab_cache_page(mapping, index); 157 if (page) 158 break; 159 yield(); 160 } 161 } else { 162 page = find_lock_page(mapping, index); 163 if (!page) 164 return NULL; 165 } 166 167 if (!page_has_buffers(page)) 168 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0); 169 170 /* Locate header for our buffer within our page */ 171 for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page) 172 /* Do nothing */; 173 get_bh(bh); 174 175 if (!buffer_mapped(bh)) 176 map_bh(bh, sdp->sd_vfs, blkno); 177 178 unlock_page(page); 179 mark_page_accessed(page); 180 page_cache_release(page); 181 182 return bh; 183 } 184 185 static void meta_prep_new(struct buffer_head *bh) 186 { 187 struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data; 188 189 lock_buffer(bh); 190 clear_buffer_dirty(bh); 191 set_buffer_uptodate(bh); 192 unlock_buffer(bh); 193 194 mh->mh_magic = cpu_to_be32(GFS2_MAGIC); 195 } 196 197 /** 198 * gfs2_meta_new - Get a block 199 * @gl: The glock associated with this block 200 * @blkno: The block number 201 * 202 * Returns: The buffer 203 */ 204 205 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno) 206 { 207 struct buffer_head *bh; 208 bh = gfs2_getbuf(gl, blkno, CREATE); 209 meta_prep_new(bh); 210 return bh; 211 } 212 213 /** 214 * gfs2_meta_read - Read a block from disk 215 * @gl: The glock covering the block 216 * @blkno: The block number 217 * @flags: flags 218 * @bhp: the place where the buffer is returned (NULL on failure) 219 * 220 * Returns: errno 221 */ 222 223 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, 224 struct buffer_head **bhp) 225 { 226 *bhp = gfs2_getbuf(gl, blkno, CREATE); 227 if (!buffer_uptodate(*bhp)) { 228 ll_rw_block(READ_META, 1, bhp); 229 if (flags & DIO_WAIT) { 230 int error = gfs2_meta_wait(gl->gl_sbd, *bhp); 231 if (error) { 232 brelse(*bhp); 233 return error; 234 } 235 } 236 } 237 238 return 0; 239 } 240 241 /** 242 * gfs2_meta_wait - Reread a block from disk 243 * @sdp: the filesystem 244 * @bh: The block to wait for 245 * 246 * Returns: errno 247 */ 248 249 int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh) 250 { 251 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 252 return -EIO; 253 254 wait_on_buffer(bh); 255 256 if (!buffer_uptodate(bh)) { 257 struct gfs2_trans *tr = current->journal_info; 258 if (tr && tr->tr_touched) 259 gfs2_io_error_bh(sdp, bh); 260 return -EIO; 261 } 262 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) 263 return -EIO; 264 265 return 0; 266 } 267 268 /** 269 * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer 270 * @gl: the glock the buffer belongs to 271 * @bh: The buffer to be attached to 272 * @meta: Flag to indicate whether its metadata or not 273 */ 274 275 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh, 276 int meta) 277 { 278 struct gfs2_bufdata *bd; 279 280 if (meta) 281 lock_page(bh->b_page); 282 283 if (bh->b_private) { 284 if (meta) 285 unlock_page(bh->b_page); 286 return; 287 } 288 289 bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL); 290 bd->bd_bh = bh; 291 bd->bd_gl = gl; 292 293 INIT_LIST_HEAD(&bd->bd_list_tr); 294 if (meta) 295 lops_init_le(&bd->bd_le, &gfs2_buf_lops); 296 else 297 lops_init_le(&bd->bd_le, &gfs2_databuf_lops); 298 bh->b_private = bd; 299 300 if (meta) 301 unlock_page(bh->b_page); 302 } 303 304 void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta) 305 { 306 struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host); 307 struct gfs2_bufdata *bd = bh->b_private; 308 if (test_clear_buffer_pinned(bh)) { 309 list_del_init(&bd->bd_le.le_list); 310 if (meta) { 311 gfs2_assert_warn(sdp, sdp->sd_log_num_buf); 312 sdp->sd_log_num_buf--; 313 tr->tr_num_buf_rm++; 314 } else { 315 gfs2_assert_warn(sdp, sdp->sd_log_num_databuf); 316 sdp->sd_log_num_databuf--; 317 tr->tr_num_databuf_rm++; 318 } 319 tr->tr_touched = 1; 320 brelse(bh); 321 } 322 if (bd) { 323 if (bd->bd_ail) { 324 gfs2_remove_from_ail(bd); 325 bh->b_private = NULL; 326 bd->bd_bh = NULL; 327 bd->bd_blkno = bh->b_blocknr; 328 gfs2_trans_add_revoke(sdp, bd); 329 } 330 } 331 clear_buffer_dirty(bh); 332 clear_buffer_uptodate(bh); 333 } 334 335 /** 336 * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore 337 * @ip: the inode who owns the buffers 338 * @bstart: the first buffer in the run 339 * @blen: the number of buffers in the run 340 * 341 */ 342 343 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen) 344 { 345 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 346 struct buffer_head *bh; 347 348 while (blen) { 349 bh = gfs2_getbuf(ip->i_gl, bstart, NO_CREATE); 350 if (bh) { 351 lock_buffer(bh); 352 gfs2_log_lock(sdp); 353 gfs2_remove_from_journal(bh, current->journal_info, 1); 354 gfs2_log_unlock(sdp); 355 unlock_buffer(bh); 356 brelse(bh); 357 } 358 359 bstart++; 360 blen--; 361 } 362 } 363 364 /** 365 * gfs2_meta_indirect_buffer - Get a metadata buffer 366 * @ip: The GFS2 inode 367 * @height: The level of this buf in the metadata (indir addr) tree (if any) 368 * @num: The block number (device relative) of the buffer 369 * @new: Non-zero if we may create a new buffer 370 * @bhp: the buffer is returned here 371 * 372 * Returns: errno 373 */ 374 375 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num, 376 int new, struct buffer_head **bhp) 377 { 378 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 379 struct gfs2_glock *gl = ip->i_gl; 380 struct buffer_head *bh; 381 int ret = 0; 382 383 if (new) { 384 BUG_ON(height == 0); 385 bh = gfs2_meta_new(gl, num); 386 gfs2_trans_add_bh(ip->i_gl, bh, 1); 387 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN); 388 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header)); 389 } else { 390 u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI; 391 ret = gfs2_meta_read(gl, num, DIO_WAIT, &bh); 392 if (ret == 0 && gfs2_metatype_check(sdp, bh, mtype)) { 393 brelse(bh); 394 ret = -EIO; 395 } 396 } 397 *bhp = bh; 398 return ret; 399 } 400 401 /** 402 * gfs2_meta_ra - start readahead on an extent of a file 403 * @gl: the glock the blocks belong to 404 * @dblock: the starting disk block 405 * @extlen: the number of blocks in the extent 406 * 407 * returns: the first buffer in the extent 408 */ 409 410 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen) 411 { 412 struct gfs2_sbd *sdp = gl->gl_sbd; 413 struct buffer_head *first_bh, *bh; 414 u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >> 415 sdp->sd_sb.sb_bsize_shift; 416 417 BUG_ON(!extlen); 418 419 if (max_ra < 1) 420 max_ra = 1; 421 if (extlen > max_ra) 422 extlen = max_ra; 423 424 first_bh = gfs2_getbuf(gl, dblock, CREATE); 425 426 if (buffer_uptodate(first_bh)) 427 goto out; 428 if (!buffer_locked(first_bh)) 429 ll_rw_block(READ_META, 1, &first_bh); 430 431 dblock++; 432 extlen--; 433 434 while (extlen) { 435 bh = gfs2_getbuf(gl, dblock, CREATE); 436 437 if (!buffer_uptodate(bh) && !buffer_locked(bh)) 438 ll_rw_block(READA, 1, &bh); 439 brelse(bh); 440 dblock++; 441 extlen--; 442 if (!buffer_locked(first_bh) && buffer_uptodate(first_bh)) 443 goto out; 444 } 445 446 wait_on_buffer(first_bh); 447 out: 448 return first_bh; 449 } 450 451