Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 1 | #include "ceph_debug.h" |
| 2 | |
| 3 | #include <linux/backing-dev.h> |
| 4 | #include <linux/fs.h> |
| 5 | #include <linux/mm.h> |
| 6 | #include <linux/pagemap.h> |
| 7 | #include <linux/writeback.h> /* generic_writepages */ |
| 8 | #include <linux/pagevec.h> |
| 9 | #include <linux/task_io_accounting_ops.h> |
| 10 | |
| 11 | #include "super.h" |
| 12 | #include "osd_client.h" |
| 13 | |
| 14 | /* |
| 15 | * Ceph address space ops. |
| 16 | * |
| 17 | * There are a few funny things going on here. |
| 18 | * |
| 19 | * The page->private field is used to reference a struct |
| 20 | * ceph_snap_context for _every_ dirty page. This indicates which |
| 21 | * snapshot the page was logically dirtied in, and thus which snap |
| 22 | * context needs to be associated with the osd write during writeback. |
| 23 | * |
| 24 | * Similarly, struct ceph_inode_info maintains a set of counters to |
| 25 | * count dirty pages on the inode. In the absense of snapshots, |
| 26 | * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count. |
| 27 | * |
| 28 | * When a snapshot is taken (that is, when the client receives |
| 29 | * notification that a snapshot was taken), each inode with caps and |
| 30 | * with dirty pages (dirty pages implies there is a cap) gets a new |
| 31 | * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending |
| 32 | * order, new snaps go to the tail). The i_wrbuffer_ref_head count is |
| 33 | * moved to capsnap->dirty. (Unless a sync write is currently in |
| 34 | * progress. In that case, the capsnap is said to be "pending", new |
| 35 | * writes cannot start, and the capsnap isn't "finalized" until the |
| 36 | * write completes (or fails) and a final size/mtime for the inode for |
| 37 | * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0. |
| 38 | * |
| 39 | * On writeback, we must submit writes to the osd IN SNAP ORDER. So, |
| 40 | * we look for the first capsnap in i_cap_snaps and write out pages in |
| 41 | * that snap context _only_. Then we move on to the next capsnap, |
| 42 | * eventually reaching the "live" or "head" context (i.e., pages that |
| 43 | * are not yet snapped) and are writing the most recently dirtied |
| 44 | * pages. |
| 45 | * |
| 46 | * Invalidate and so forth must take care to ensure the dirty page |
| 47 | * accounting is preserved. |
| 48 | */ |
| 49 | |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 50 | #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10)) |
| 51 | #define CONGESTION_OFF_THRESH(congestion_kb) \ |
| 52 | (CONGESTION_ON_THRESH(congestion_kb) - \ |
| 53 | (CONGESTION_ON_THRESH(congestion_kb) >> 2)) |
| 54 | |
| 55 | |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 56 | |
| 57 | /* |
| 58 | * Dirty a page. Optimistically adjust accounting, on the assumption |
| 59 | * that we won't race with invalidate. If we do, readjust. |
| 60 | */ |
| 61 | static int ceph_set_page_dirty(struct page *page) |
| 62 | { |
| 63 | struct address_space *mapping = page->mapping; |
| 64 | struct inode *inode; |
| 65 | struct ceph_inode_info *ci; |
| 66 | int undo = 0; |
| 67 | struct ceph_snap_context *snapc; |
| 68 | |
| 69 | if (unlikely(!mapping)) |
| 70 | return !TestSetPageDirty(page); |
| 71 | |
| 72 | if (TestSetPageDirty(page)) { |
| 73 | dout("%p set_page_dirty %p idx %lu -- already dirty\n", |
| 74 | mapping->host, page, page->index); |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | inode = mapping->host; |
| 79 | ci = ceph_inode(inode); |
| 80 | |
| 81 | /* |
| 82 | * Note that we're grabbing a snapc ref here without holding |
| 83 | * any locks! |
| 84 | */ |
| 85 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); |
| 86 | |
| 87 | /* dirty the head */ |
| 88 | spin_lock(&inode->i_lock); |
| 89 | if (ci->i_wrbuffer_ref_head == 0) |
| 90 | ci->i_head_snapc = ceph_get_snap_context(snapc); |
| 91 | ++ci->i_wrbuffer_ref_head; |
| 92 | if (ci->i_wrbuffer_ref == 0) |
| 93 | igrab(inode); |
| 94 | ++ci->i_wrbuffer_ref; |
| 95 | dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " |
| 96 | "snapc %p seq %lld (%d snaps)\n", |
| 97 | mapping->host, page, page->index, |
| 98 | ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1, |
| 99 | ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, |
| 100 | snapc, snapc->seq, snapc->num_snaps); |
| 101 | spin_unlock(&inode->i_lock); |
| 102 | |
| 103 | /* now adjust page */ |
| 104 | spin_lock_irq(&mapping->tree_lock); |
| 105 | if (page->mapping) { /* Race with truncate? */ |
| 106 | WARN_ON_ONCE(!PageUptodate(page)); |
| 107 | |
| 108 | if (mapping_cap_account_dirty(mapping)) { |
| 109 | __inc_zone_page_state(page, NR_FILE_DIRTY); |
| 110 | __inc_bdi_stat(mapping->backing_dev_info, |
| 111 | BDI_RECLAIMABLE); |
| 112 | task_io_account_write(PAGE_CACHE_SIZE); |
| 113 | } |
| 114 | radix_tree_tag_set(&mapping->page_tree, |
| 115 | page_index(page), PAGECACHE_TAG_DIRTY); |
| 116 | |
| 117 | /* |
| 118 | * Reference snap context in page->private. Also set |
| 119 | * PagePrivate so that we get invalidatepage callback. |
| 120 | */ |
| 121 | page->private = (unsigned long)snapc; |
| 122 | SetPagePrivate(page); |
| 123 | } else { |
| 124 | dout("ANON set_page_dirty %p (raced truncate?)\n", page); |
| 125 | undo = 1; |
| 126 | } |
| 127 | |
| 128 | spin_unlock_irq(&mapping->tree_lock); |
| 129 | |
| 130 | if (undo) |
| 131 | /* whoops, we failed to dirty the page */ |
| 132 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); |
| 133 | |
| 134 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); |
| 135 | |
| 136 | BUG_ON(!PageDirty(page)); |
| 137 | return 1; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * If we are truncating the full page (i.e. offset == 0), adjust the |
| 142 | * dirty page counters appropriately. Only called if there is private |
| 143 | * data on the page. |
| 144 | */ |
| 145 | static void ceph_invalidatepage(struct page *page, unsigned long offset) |
| 146 | { |
| 147 | struct inode *inode = page->mapping->host; |
| 148 | struct ceph_inode_info *ci; |
| 149 | struct ceph_snap_context *snapc = (void *)page->private; |
| 150 | |
| 151 | BUG_ON(!PageLocked(page)); |
| 152 | BUG_ON(!page->private); |
| 153 | BUG_ON(!PagePrivate(page)); |
| 154 | BUG_ON(!page->mapping); |
| 155 | |
| 156 | /* |
| 157 | * We can get non-dirty pages here due to races between |
| 158 | * set_page_dirty and truncate_complete_page; just spit out a |
| 159 | * warning, in case we end up with accounting problems later. |
| 160 | */ |
| 161 | if (!PageDirty(page)) |
| 162 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); |
| 163 | |
| 164 | if (offset == 0) |
| 165 | ClearPageChecked(page); |
| 166 | |
| 167 | ci = ceph_inode(inode); |
| 168 | if (offset == 0) { |
| 169 | dout("%p invalidatepage %p idx %lu full dirty page %lu\n", |
| 170 | inode, page, page->index, offset); |
| 171 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); |
| 172 | ceph_put_snap_context(snapc); |
| 173 | page->private = 0; |
| 174 | ClearPagePrivate(page); |
| 175 | } else { |
| 176 | dout("%p invalidatepage %p idx %lu partial dirty page\n", |
| 177 | inode, page, page->index); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | /* just a sanity check */ |
| 182 | static int ceph_releasepage(struct page *page, gfp_t g) |
| 183 | { |
| 184 | struct inode *inode = page->mapping ? page->mapping->host : NULL; |
| 185 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); |
| 186 | WARN_ON(PageDirty(page)); |
| 187 | WARN_ON(page->private); |
| 188 | WARN_ON(PagePrivate(page)); |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * read a single page, without unlocking it. |
| 194 | */ |
| 195 | static int readpage_nounlock(struct file *filp, struct page *page) |
| 196 | { |
| 197 | struct inode *inode = filp->f_dentry->d_inode; |
| 198 | struct ceph_inode_info *ci = ceph_inode(inode); |
| 199 | struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc; |
| 200 | int err = 0; |
| 201 | u64 len = PAGE_CACHE_SIZE; |
| 202 | |
| 203 | dout("readpage inode %p file %p page %p index %lu\n", |
| 204 | inode, filp, page, page->index); |
| 205 | err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, |
| 206 | page->index << PAGE_CACHE_SHIFT, &len, |
| 207 | ci->i_truncate_seq, ci->i_truncate_size, |
| 208 | &page, 1); |
| 209 | if (err == -ENOENT) |
| 210 | err = 0; |
| 211 | if (err < 0) { |
| 212 | SetPageError(page); |
| 213 | goto out; |
| 214 | } else if (err < PAGE_CACHE_SIZE) { |
| 215 | /* zero fill remainder of page */ |
| 216 | zero_user_segment(page, err, PAGE_CACHE_SIZE); |
| 217 | } |
| 218 | SetPageUptodate(page); |
| 219 | |
| 220 | out: |
| 221 | return err < 0 ? err : 0; |
| 222 | } |
| 223 | |
| 224 | static int ceph_readpage(struct file *filp, struct page *page) |
| 225 | { |
| 226 | int r = readpage_nounlock(filp, page); |
| 227 | unlock_page(page); |
| 228 | return r; |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * Build a vector of contiguous pages from the provided page list. |
| 233 | */ |
| 234 | static struct page **page_vector_from_list(struct list_head *page_list, |
| 235 | unsigned *nr_pages) |
| 236 | { |
| 237 | struct page **pages; |
| 238 | struct page *page; |
| 239 | int next_index, contig_pages = 0; |
| 240 | |
| 241 | /* build page vector */ |
| 242 | pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS); |
| 243 | if (!pages) |
| 244 | return ERR_PTR(-ENOMEM); |
| 245 | |
| 246 | BUG_ON(list_empty(page_list)); |
| 247 | next_index = list_entry(page_list->prev, struct page, lru)->index; |
| 248 | list_for_each_entry_reverse(page, page_list, lru) { |
| 249 | if (page->index == next_index) { |
| 250 | dout("readpages page %d %p\n", contig_pages, page); |
| 251 | pages[contig_pages] = page; |
| 252 | contig_pages++; |
| 253 | next_index++; |
| 254 | } else { |
| 255 | break; |
| 256 | } |
| 257 | } |
| 258 | *nr_pages = contig_pages; |
| 259 | return pages; |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * Read multiple pages. Leave pages we don't read + unlock in page_list; |
| 264 | * the caller (VM) cleans them up. |
| 265 | */ |
| 266 | static int ceph_readpages(struct file *file, struct address_space *mapping, |
| 267 | struct list_head *page_list, unsigned nr_pages) |
| 268 | { |
| 269 | struct inode *inode = file->f_dentry->d_inode; |
| 270 | struct ceph_inode_info *ci = ceph_inode(inode); |
| 271 | struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc; |
| 272 | int rc = 0; |
| 273 | struct page **pages; |
| 274 | struct pagevec pvec; |
| 275 | loff_t offset; |
| 276 | u64 len; |
| 277 | |
| 278 | dout("readpages %p file %p nr_pages %d\n", |
| 279 | inode, file, nr_pages); |
| 280 | |
| 281 | pages = page_vector_from_list(page_list, &nr_pages); |
| 282 | if (IS_ERR(pages)) |
| 283 | return PTR_ERR(pages); |
| 284 | |
| 285 | /* guess read extent */ |
| 286 | offset = pages[0]->index << PAGE_CACHE_SHIFT; |
| 287 | len = nr_pages << PAGE_CACHE_SHIFT; |
| 288 | rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, |
| 289 | offset, &len, |
| 290 | ci->i_truncate_seq, ci->i_truncate_size, |
| 291 | pages, nr_pages); |
| 292 | if (rc == -ENOENT) |
| 293 | rc = 0; |
| 294 | if (rc < 0) |
| 295 | goto out; |
| 296 | |
| 297 | /* set uptodate and add to lru in pagevec-sized chunks */ |
| 298 | pagevec_init(&pvec, 0); |
| 299 | for (; !list_empty(page_list) && len > 0; |
| 300 | rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) { |
| 301 | struct page *page = |
| 302 | list_entry(page_list->prev, struct page, lru); |
| 303 | |
| 304 | list_del(&page->lru); |
| 305 | |
| 306 | if (rc < (int)PAGE_CACHE_SIZE) { |
| 307 | /* zero (remainder of) page */ |
| 308 | int s = rc < 0 ? 0 : rc; |
| 309 | zero_user_segment(page, s, PAGE_CACHE_SIZE); |
| 310 | } |
| 311 | |
| 312 | if (add_to_page_cache(page, mapping, page->index, GFP_NOFS)) { |
| 313 | page_cache_release(page); |
| 314 | dout("readpages %p add_to_page_cache failed %p\n", |
| 315 | inode, page); |
| 316 | continue; |
| 317 | } |
| 318 | dout("readpages %p adding %p idx %lu\n", inode, page, |
| 319 | page->index); |
| 320 | flush_dcache_page(page); |
| 321 | SetPageUptodate(page); |
| 322 | unlock_page(page); |
| 323 | if (pagevec_add(&pvec, page) == 0) |
| 324 | pagevec_lru_add_file(&pvec); /* add to lru */ |
| 325 | } |
| 326 | pagevec_lru_add_file(&pvec); |
| 327 | rc = 0; |
| 328 | |
| 329 | out: |
| 330 | kfree(pages); |
| 331 | return rc; |
| 332 | } |
| 333 | |
| 334 | /* |
| 335 | * Get ref for the oldest snapc for an inode with dirty data... that is, the |
| 336 | * only snap context we are allowed to write back. |
| 337 | * |
| 338 | * Caller holds i_lock. |
| 339 | */ |
| 340 | static struct ceph_snap_context *__get_oldest_context(struct inode *inode, |
| 341 | u64 *snap_size) |
| 342 | { |
| 343 | struct ceph_inode_info *ci = ceph_inode(inode); |
| 344 | struct ceph_snap_context *snapc = NULL; |
| 345 | struct ceph_cap_snap *capsnap = NULL; |
| 346 | |
| 347 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
| 348 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, |
| 349 | capsnap->context, capsnap->dirty_pages); |
| 350 | if (capsnap->dirty_pages) { |
| 351 | snapc = ceph_get_snap_context(capsnap->context); |
| 352 | if (snap_size) |
| 353 | *snap_size = capsnap->size; |
| 354 | break; |
| 355 | } |
| 356 | } |
| 357 | if (!snapc && ci->i_snap_realm) { |
| 358 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); |
| 359 | dout(" head snapc %p has %d dirty pages\n", |
| 360 | snapc, ci->i_wrbuffer_ref_head); |
| 361 | } |
| 362 | return snapc; |
| 363 | } |
| 364 | |
| 365 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
| 366 | u64 *snap_size) |
| 367 | { |
| 368 | struct ceph_snap_context *snapc = NULL; |
| 369 | |
| 370 | spin_lock(&inode->i_lock); |
| 371 | snapc = __get_oldest_context(inode, snap_size); |
| 372 | spin_unlock(&inode->i_lock); |
| 373 | return snapc; |
| 374 | } |
| 375 | |
| 376 | /* |
| 377 | * Write a single page, but leave the page locked. |
| 378 | * |
| 379 | * If we get a write error, set the page error bit, but still adjust the |
| 380 | * dirty page accounting (i.e., page is no longer dirty). |
| 381 | */ |
| 382 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) |
| 383 | { |
| 384 | struct inode *inode; |
| 385 | struct ceph_inode_info *ci; |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 386 | struct ceph_client *client; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 387 | struct ceph_osd_client *osdc; |
| 388 | loff_t page_off = page->index << PAGE_CACHE_SHIFT; |
| 389 | int len = PAGE_CACHE_SIZE; |
| 390 | loff_t i_size; |
| 391 | int err = 0; |
| 392 | struct ceph_snap_context *snapc; |
| 393 | u64 snap_size = 0; |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 394 | long writeback_stat; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 395 | |
| 396 | dout("writepage %p idx %lu\n", page, page->index); |
| 397 | |
| 398 | if (!page->mapping || !page->mapping->host) { |
| 399 | dout("writepage %p - no mapping\n", page); |
| 400 | return -EFAULT; |
| 401 | } |
| 402 | inode = page->mapping->host; |
| 403 | ci = ceph_inode(inode); |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 404 | client = ceph_inode_to_client(inode); |
| 405 | osdc = &client->osdc; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 406 | |
| 407 | /* verify this is a writeable snap context */ |
| 408 | snapc = (void *)page->private; |
| 409 | if (snapc == NULL) { |
| 410 | dout("writepage %p page %p not dirty?\n", inode, page); |
| 411 | goto out; |
| 412 | } |
| 413 | if (snapc != get_oldest_context(inode, &snap_size)) { |
| 414 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
| 415 | inode, page, (void *)page->private); |
| 416 | /* we should only noop if called by kswapd */ |
| 417 | WARN_ON((current->flags & PF_MEMALLOC) == 0); |
| 418 | goto out; |
| 419 | } |
| 420 | |
| 421 | /* is this a partial page at end of file? */ |
| 422 | if (snap_size) |
| 423 | i_size = snap_size; |
| 424 | else |
| 425 | i_size = i_size_read(inode); |
| 426 | if (i_size < page_off + len) |
| 427 | len = i_size - page_off; |
| 428 | |
| 429 | dout("writepage %p page %p index %lu on %llu~%u\n", |
| 430 | inode, page, page->index, page_off, len); |
| 431 | |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 432 | writeback_stat = atomic_long_inc_return(&client->writeback_count); |
| 433 | if (writeback_stat > |
| 434 | CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) |
| 435 | set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC); |
| 436 | |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 437 | set_page_writeback(page); |
| 438 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), |
| 439 | &ci->i_layout, snapc, |
| 440 | page_off, len, |
| 441 | ci->i_truncate_seq, ci->i_truncate_size, |
| 442 | &inode->i_mtime, |
| 443 | &page, 1, 0, 0, true); |
| 444 | if (err < 0) { |
| 445 | dout("writepage setting page/mapping error %d %p\n", err, page); |
| 446 | SetPageError(page); |
| 447 | mapping_set_error(&inode->i_data, err); |
| 448 | if (wbc) |
| 449 | wbc->pages_skipped++; |
| 450 | } else { |
| 451 | dout("writepage cleaned page %p\n", page); |
| 452 | err = 0; /* vfs expects us to return 0 */ |
| 453 | } |
| 454 | page->private = 0; |
| 455 | ClearPagePrivate(page); |
| 456 | end_page_writeback(page); |
| 457 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); |
| 458 | ceph_put_snap_context(snapc); |
| 459 | out: |
| 460 | return err; |
| 461 | } |
| 462 | |
| 463 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) |
| 464 | { |
Yehuda Sadeh | dbd646a | 2009-12-16 14:51:06 -0800 | [diff] [blame] | 465 | int err; |
| 466 | struct inode *inode = page->mapping->host; |
| 467 | BUG_ON(!inode); |
| 468 | igrab(inode); |
| 469 | err = writepage_nounlock(page, wbc); |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 470 | unlock_page(page); |
Yehuda Sadeh | dbd646a | 2009-12-16 14:51:06 -0800 | [diff] [blame] | 471 | iput(inode); |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 472 | return err; |
| 473 | } |
| 474 | |
| 475 | |
| 476 | /* |
| 477 | * lame release_pages helper. release_pages() isn't exported to |
| 478 | * modules. |
| 479 | */ |
| 480 | static void ceph_release_pages(struct page **pages, int num) |
| 481 | { |
| 482 | struct pagevec pvec; |
| 483 | int i; |
| 484 | |
| 485 | pagevec_init(&pvec, 0); |
| 486 | for (i = 0; i < num; i++) { |
| 487 | if (pagevec_add(&pvec, pages[i]) == 0) |
| 488 | pagevec_release(&pvec); |
| 489 | } |
| 490 | pagevec_release(&pvec); |
| 491 | } |
| 492 | |
| 493 | |
| 494 | /* |
| 495 | * async writeback completion handler. |
| 496 | * |
| 497 | * If we get an error, set the mapping error bit, but not the individual |
| 498 | * page error bits. |
| 499 | */ |
| 500 | static void writepages_finish(struct ceph_osd_request *req, |
| 501 | struct ceph_msg *msg) |
| 502 | { |
| 503 | struct inode *inode = req->r_inode; |
| 504 | struct ceph_osd_reply_head *replyhead; |
| 505 | struct ceph_osd_op *op; |
| 506 | struct ceph_inode_info *ci = ceph_inode(inode); |
| 507 | unsigned wrote; |
| 508 | loff_t offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT; |
| 509 | struct page *page; |
| 510 | int i; |
| 511 | struct ceph_snap_context *snapc = req->r_snapc; |
| 512 | struct address_space *mapping = inode->i_mapping; |
| 513 | struct writeback_control *wbc = req->r_wbc; |
| 514 | __s32 rc = -EIO; |
| 515 | u64 bytes = 0; |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 516 | struct ceph_client *client = ceph_inode_to_client(inode); |
| 517 | long writeback_stat; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 518 | |
| 519 | /* parse reply */ |
| 520 | replyhead = msg->front.iov_base; |
| 521 | WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); |
| 522 | op = (void *)(replyhead + 1); |
| 523 | rc = le32_to_cpu(replyhead->result); |
| 524 | bytes = le64_to_cpu(op->extent.length); |
| 525 | |
| 526 | if (rc >= 0) { |
| 527 | wrote = (bytes + (offset & ~PAGE_CACHE_MASK) + ~PAGE_CACHE_MASK) |
| 528 | >> PAGE_CACHE_SHIFT; |
| 529 | WARN_ON(wrote != req->r_num_pages); |
| 530 | } else { |
| 531 | wrote = 0; |
| 532 | mapping_set_error(mapping, rc); |
| 533 | } |
| 534 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", |
| 535 | inode, rc, bytes, wrote); |
| 536 | |
| 537 | /* clean all pages */ |
| 538 | for (i = 0; i < req->r_num_pages; i++) { |
| 539 | page = req->r_pages[i]; |
| 540 | BUG_ON(!page); |
| 541 | WARN_ON(!PageUptodate(page)); |
| 542 | |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 543 | writeback_stat = |
| 544 | atomic_long_dec_return(&client->writeback_count); |
| 545 | if (writeback_stat < |
| 546 | CONGESTION_OFF_THRESH(client->mount_args->congestion_kb)) |
| 547 | clear_bdi_congested(&client->backing_dev_info, |
| 548 | BLK_RW_ASYNC); |
| 549 | |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 550 | if (i >= wrote) { |
| 551 | dout("inode %p skipping page %p\n", inode, page); |
| 552 | wbc->pages_skipped++; |
| 553 | } |
| 554 | page->private = 0; |
| 555 | ClearPagePrivate(page); |
| 556 | ceph_put_snap_context(snapc); |
| 557 | dout("unlocking %d %p\n", i, page); |
| 558 | end_page_writeback(page); |
| 559 | unlock_page(page); |
| 560 | } |
| 561 | dout("%p wrote+cleaned %d pages\n", inode, wrote); |
| 562 | ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc); |
| 563 | |
| 564 | ceph_release_pages(req->r_pages, req->r_num_pages); |
| 565 | if (req->r_pages_from_pool) |
| 566 | mempool_free(req->r_pages, |
| 567 | ceph_client(inode->i_sb)->wb_pagevec_pool); |
| 568 | else |
| 569 | kfree(req->r_pages); |
| 570 | ceph_osdc_put_request(req); |
| 571 | } |
| 572 | |
| 573 | /* |
| 574 | * allocate a page vec, either directly, or if necessary, via a the |
| 575 | * mempool. we avoid the mempool if we can because req->r_num_pages |
| 576 | * may be less than the maximum write size. |
| 577 | */ |
| 578 | static void alloc_page_vec(struct ceph_client *client, |
| 579 | struct ceph_osd_request *req) |
| 580 | { |
| 581 | req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages, |
| 582 | GFP_NOFS); |
| 583 | if (!req->r_pages) { |
| 584 | req->r_pages = mempool_alloc(client->wb_pagevec_pool, GFP_NOFS); |
| 585 | req->r_pages_from_pool = 1; |
| 586 | WARN_ON(!req->r_pages); |
| 587 | } |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * initiate async writeback |
| 592 | */ |
| 593 | static int ceph_writepages_start(struct address_space *mapping, |
| 594 | struct writeback_control *wbc) |
| 595 | { |
| 596 | struct inode *inode = mapping->host; |
| 597 | struct backing_dev_info *bdi = mapping->backing_dev_info; |
| 598 | struct ceph_inode_info *ci = ceph_inode(inode); |
Julia Lawall | ec7384e | 2010-01-20 15:16:41 -0800 | [diff] [blame^] | 599 | struct ceph_client *client; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 600 | pgoff_t index, start, end; |
| 601 | int range_whole = 0; |
| 602 | int should_loop = 1; |
| 603 | pgoff_t max_pages = 0, max_pages_ever = 0; |
| 604 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL; |
| 605 | struct pagevec pvec; |
| 606 | int done = 0; |
| 607 | int rc = 0; |
| 608 | unsigned wsize = 1 << inode->i_blkbits; |
| 609 | struct ceph_osd_request *req = NULL; |
| 610 | int do_sync; |
| 611 | u64 snap_size = 0; |
| 612 | |
| 613 | /* |
| 614 | * Include a 'sync' in the OSD request if this is a data |
| 615 | * integrity write (e.g., O_SYNC write or fsync()), or if our |
| 616 | * cap is being revoked. |
| 617 | */ |
| 618 | do_sync = wbc->sync_mode == WB_SYNC_ALL; |
| 619 | if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) |
| 620 | do_sync = 1; |
| 621 | dout("writepages_start %p dosync=%d (mode=%s)\n", |
| 622 | inode, do_sync, |
| 623 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : |
| 624 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); |
| 625 | |
| 626 | client = ceph_inode_to_client(inode); |
| 627 | if (client->mount_state == CEPH_MOUNT_SHUTDOWN) { |
| 628 | pr_warning("writepage_start %p on forced umount\n", inode); |
| 629 | return -EIO; /* we're in a forced umount, don't write! */ |
| 630 | } |
Sage Weil | 6b80518 | 2009-10-27 11:50:50 -0700 | [diff] [blame] | 631 | if (client->mount_args->wsize && client->mount_args->wsize < wsize) |
| 632 | wsize = client->mount_args->wsize; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 633 | if (wsize < PAGE_CACHE_SIZE) |
| 634 | wsize = PAGE_CACHE_SIZE; |
| 635 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; |
| 636 | |
| 637 | pagevec_init(&pvec, 0); |
| 638 | |
| 639 | /* ?? */ |
| 640 | if (wbc->nonblocking && bdi_write_congested(bdi)) { |
| 641 | dout(" writepages congested\n"); |
| 642 | wbc->encountered_congestion = 1; |
| 643 | goto out_final; |
| 644 | } |
| 645 | |
| 646 | /* where to start/end? */ |
| 647 | if (wbc->range_cyclic) { |
| 648 | start = mapping->writeback_index; /* Start from prev offset */ |
| 649 | end = -1; |
| 650 | dout(" cyclic, start at %lu\n", start); |
| 651 | } else { |
| 652 | start = wbc->range_start >> PAGE_CACHE_SHIFT; |
| 653 | end = wbc->range_end >> PAGE_CACHE_SHIFT; |
| 654 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| 655 | range_whole = 1; |
| 656 | should_loop = 0; |
| 657 | dout(" not cyclic, %lu to %lu\n", start, end); |
| 658 | } |
| 659 | index = start; |
| 660 | |
| 661 | retry: |
| 662 | /* find oldest snap context with dirty data */ |
| 663 | ceph_put_snap_context(snapc); |
| 664 | snapc = get_oldest_context(inode, &snap_size); |
| 665 | if (!snapc) { |
| 666 | /* hmm, why does writepages get called when there |
| 667 | is no dirty data? */ |
| 668 | dout(" no snap context with dirty data?\n"); |
| 669 | goto out; |
| 670 | } |
| 671 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", |
| 672 | snapc, snapc->seq, snapc->num_snaps); |
| 673 | if (last_snapc && snapc != last_snapc) { |
| 674 | /* if we switched to a newer snapc, restart our scan at the |
| 675 | * start of the original file range. */ |
| 676 | dout(" snapc differs from last pass, restarting at %lu\n", |
| 677 | index); |
| 678 | index = start; |
| 679 | } |
| 680 | last_snapc = snapc; |
| 681 | |
| 682 | while (!done && index <= end) { |
| 683 | unsigned i; |
| 684 | int first; |
| 685 | pgoff_t next; |
| 686 | int pvec_pages, locked_pages; |
| 687 | struct page *page; |
| 688 | int want; |
| 689 | u64 offset, len; |
| 690 | struct ceph_osd_request_head *reqhead; |
| 691 | struct ceph_osd_op *op; |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 692 | long writeback_stat; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 693 | |
| 694 | next = 0; |
| 695 | locked_pages = 0; |
| 696 | max_pages = max_pages_ever; |
| 697 | |
| 698 | get_more_pages: |
| 699 | first = -1; |
| 700 | want = min(end - index, |
| 701 | min((pgoff_t)PAGEVEC_SIZE, |
| 702 | max_pages - (pgoff_t)locked_pages) - 1) |
| 703 | + 1; |
| 704 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, |
| 705 | PAGECACHE_TAG_DIRTY, |
| 706 | want); |
| 707 | dout("pagevec_lookup_tag got %d\n", pvec_pages); |
| 708 | if (!pvec_pages && !locked_pages) |
| 709 | break; |
| 710 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { |
| 711 | page = pvec.pages[i]; |
| 712 | dout("? %p idx %lu\n", page, page->index); |
| 713 | if (locked_pages == 0) |
| 714 | lock_page(page); /* first page */ |
| 715 | else if (!trylock_page(page)) |
| 716 | break; |
| 717 | |
| 718 | /* only dirty pages, or our accounting breaks */ |
| 719 | if (unlikely(!PageDirty(page)) || |
| 720 | unlikely(page->mapping != mapping)) { |
| 721 | dout("!dirty or !mapping %p\n", page); |
| 722 | unlock_page(page); |
| 723 | break; |
| 724 | } |
| 725 | if (!wbc->range_cyclic && page->index > end) { |
| 726 | dout("end of range %p\n", page); |
| 727 | done = 1; |
| 728 | unlock_page(page); |
| 729 | break; |
| 730 | } |
| 731 | if (next && (page->index != next)) { |
| 732 | dout("not consecutive %p\n", page); |
| 733 | unlock_page(page); |
| 734 | break; |
| 735 | } |
| 736 | if (wbc->sync_mode != WB_SYNC_NONE) { |
| 737 | dout("waiting on writeback %p\n", page); |
| 738 | wait_on_page_writeback(page); |
| 739 | } |
| 740 | if ((snap_size && page_offset(page) > snap_size) || |
| 741 | (!snap_size && |
| 742 | page_offset(page) > i_size_read(inode))) { |
| 743 | dout("%p page eof %llu\n", page, snap_size ? |
| 744 | snap_size : i_size_read(inode)); |
| 745 | done = 1; |
| 746 | unlock_page(page); |
| 747 | break; |
| 748 | } |
| 749 | if (PageWriteback(page)) { |
| 750 | dout("%p under writeback\n", page); |
| 751 | unlock_page(page); |
| 752 | break; |
| 753 | } |
| 754 | |
| 755 | /* only if matching snap context */ |
| 756 | if (snapc != (void *)page->private) { |
| 757 | dout("page snapc %p != oldest %p\n", |
| 758 | (void *)page->private, snapc); |
| 759 | unlock_page(page); |
| 760 | if (!locked_pages) |
| 761 | continue; /* keep looking for snap */ |
| 762 | break; |
| 763 | } |
| 764 | |
| 765 | if (!clear_page_dirty_for_io(page)) { |
| 766 | dout("%p !clear_page_dirty_for_io\n", page); |
| 767 | unlock_page(page); |
| 768 | break; |
| 769 | } |
| 770 | |
| 771 | /* ok */ |
| 772 | if (locked_pages == 0) { |
| 773 | /* prepare async write request */ |
| 774 | offset = page->index << PAGE_CACHE_SHIFT; |
| 775 | len = wsize; |
| 776 | req = ceph_osdc_new_request(&client->osdc, |
| 777 | &ci->i_layout, |
| 778 | ceph_vino(inode), |
| 779 | offset, &len, |
| 780 | CEPH_OSD_OP_WRITE, |
| 781 | CEPH_OSD_FLAG_WRITE | |
| 782 | CEPH_OSD_FLAG_ONDISK, |
| 783 | snapc, do_sync, |
| 784 | ci->i_truncate_seq, |
| 785 | ci->i_truncate_size, |
| 786 | &inode->i_mtime, true, 1); |
| 787 | max_pages = req->r_num_pages; |
| 788 | |
| 789 | alloc_page_vec(client, req); |
| 790 | req->r_callback = writepages_finish; |
| 791 | req->r_inode = inode; |
| 792 | req->r_wbc = wbc; |
| 793 | } |
| 794 | |
| 795 | /* note position of first page in pvec */ |
| 796 | if (first < 0) |
| 797 | first = i; |
| 798 | dout("%p will write page %p idx %lu\n", |
| 799 | inode, page, page->index); |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 800 | |
| 801 | writeback_stat = atomic_long_inc_return(&client->writeback_count); |
| 802 | if (writeback_stat > CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) { |
| 803 | set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC); |
| 804 | } |
| 805 | |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 806 | set_page_writeback(page); |
| 807 | req->r_pages[locked_pages] = page; |
| 808 | locked_pages++; |
| 809 | next = page->index + 1; |
| 810 | } |
| 811 | |
| 812 | /* did we get anything? */ |
| 813 | if (!locked_pages) |
| 814 | goto release_pvec_pages; |
| 815 | if (i) { |
| 816 | int j; |
| 817 | BUG_ON(!locked_pages || first < 0); |
| 818 | |
| 819 | if (pvec_pages && i == pvec_pages && |
| 820 | locked_pages < max_pages) { |
| 821 | dout("reached end pvec, trying for more\n"); |
| 822 | pagevec_reinit(&pvec); |
| 823 | goto get_more_pages; |
| 824 | } |
| 825 | |
| 826 | /* shift unused pages over in the pvec... we |
| 827 | * will need to release them below. */ |
| 828 | for (j = i; j < pvec_pages; j++) { |
| 829 | dout(" pvec leftover page %p\n", |
| 830 | pvec.pages[j]); |
| 831 | pvec.pages[j-i+first] = pvec.pages[j]; |
| 832 | } |
| 833 | pvec.nr -= i-first; |
| 834 | } |
| 835 | |
| 836 | /* submit the write */ |
| 837 | offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT; |
| 838 | len = min((snap_size ? snap_size : i_size_read(inode)) - offset, |
| 839 | (u64)locked_pages << PAGE_CACHE_SHIFT); |
| 840 | dout("writepages got %d pages at %llu~%llu\n", |
| 841 | locked_pages, offset, len); |
| 842 | |
| 843 | /* revise final length, page count */ |
| 844 | req->r_num_pages = locked_pages; |
| 845 | reqhead = req->r_request->front.iov_base; |
| 846 | op = (void *)(reqhead + 1); |
| 847 | op->extent.length = cpu_to_le64(len); |
| 848 | op->payload_len = cpu_to_le32(len); |
| 849 | req->r_request->hdr.data_len = cpu_to_le32(len); |
| 850 | |
| 851 | ceph_osdc_start_request(&client->osdc, req, true); |
| 852 | req = NULL; |
| 853 | |
| 854 | /* continue? */ |
| 855 | index = next; |
| 856 | wbc->nr_to_write -= locked_pages; |
| 857 | if (wbc->nr_to_write <= 0) |
| 858 | done = 1; |
| 859 | |
| 860 | release_pvec_pages: |
| 861 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, |
| 862 | pvec.nr ? pvec.pages[0] : NULL); |
| 863 | pagevec_release(&pvec); |
| 864 | |
| 865 | if (locked_pages && !done) |
| 866 | goto retry; |
| 867 | } |
| 868 | |
| 869 | if (should_loop && !done) { |
| 870 | /* more to do; loop back to beginning of file */ |
| 871 | dout("writepages looping back to beginning of file\n"); |
| 872 | should_loop = 0; |
| 873 | index = 0; |
| 874 | goto retry; |
| 875 | } |
| 876 | |
| 877 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) |
| 878 | mapping->writeback_index = index; |
| 879 | |
| 880 | out: |
| 881 | if (req) |
| 882 | ceph_osdc_put_request(req); |
| 883 | if (rc > 0) |
| 884 | rc = 0; /* vfs expects us to return 0 */ |
| 885 | ceph_put_snap_context(snapc); |
| 886 | dout("writepages done, rc = %d\n", rc); |
| 887 | out_final: |
| 888 | return rc; |
| 889 | } |
| 890 | |
| 891 | |
| 892 | |
| 893 | /* |
| 894 | * See if a given @snapc is either writeable, or already written. |
| 895 | */ |
| 896 | static int context_is_writeable_or_written(struct inode *inode, |
| 897 | struct ceph_snap_context *snapc) |
| 898 | { |
| 899 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); |
| 900 | return !oldest || snapc->seq <= oldest->seq; |
| 901 | } |
| 902 | |
| 903 | /* |
| 904 | * We are only allowed to write into/dirty the page if the page is |
| 905 | * clean, or already dirty within the same snap context. |
| 906 | */ |
| 907 | static int ceph_write_begin(struct file *file, struct address_space *mapping, |
| 908 | loff_t pos, unsigned len, unsigned flags, |
| 909 | struct page **pagep, void **fsdata) |
| 910 | { |
| 911 | struct inode *inode = file->f_dentry->d_inode; |
| 912 | struct ceph_inode_info *ci = ceph_inode(inode); |
| 913 | struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; |
| 914 | struct page *page; |
| 915 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| 916 | loff_t page_off = pos & PAGE_CACHE_MASK; |
| 917 | int pos_in_page = pos & ~PAGE_CACHE_MASK; |
| 918 | int end_in_page = pos_in_page + len; |
| 919 | loff_t i_size; |
| 920 | struct ceph_snap_context *snapc; |
| 921 | int r; |
| 922 | |
| 923 | /* get a page*/ |
| 924 | retry: |
| 925 | page = grab_cache_page_write_begin(mapping, index, 0); |
| 926 | if (!page) |
| 927 | return -ENOMEM; |
| 928 | *pagep = page; |
| 929 | |
| 930 | dout("write_begin file %p inode %p page %p %d~%d\n", file, |
| 931 | inode, page, (int)pos, (int)len); |
| 932 | |
| 933 | retry_locked: |
| 934 | /* writepages currently holds page lock, but if we change that later, */ |
| 935 | wait_on_page_writeback(page); |
| 936 | |
| 937 | /* check snap context */ |
| 938 | BUG_ON(!ci->i_snap_realm); |
| 939 | down_read(&mdsc->snap_rwsem); |
| 940 | BUG_ON(!ci->i_snap_realm->cached_context); |
| 941 | if (page->private && |
| 942 | (void *)page->private != ci->i_snap_realm->cached_context) { |
| 943 | /* |
| 944 | * this page is already dirty in another (older) snap |
| 945 | * context! is it writeable now? |
| 946 | */ |
| 947 | snapc = get_oldest_context(inode, NULL); |
| 948 | up_read(&mdsc->snap_rwsem); |
| 949 | |
| 950 | if (snapc != (void *)page->private) { |
| 951 | dout(" page %p snapc %p not current or oldest\n", |
| 952 | page, (void *)page->private); |
| 953 | /* |
| 954 | * queue for writeback, and wait for snapc to |
| 955 | * be writeable or written |
| 956 | */ |
| 957 | snapc = ceph_get_snap_context((void *)page->private); |
| 958 | unlock_page(page); |
| 959 | if (ceph_queue_writeback(inode)) |
| 960 | igrab(inode); |
| 961 | wait_event_interruptible(ci->i_cap_wq, |
| 962 | context_is_writeable_or_written(inode, snapc)); |
| 963 | ceph_put_snap_context(snapc); |
| 964 | goto retry; |
| 965 | } |
| 966 | |
| 967 | /* yay, writeable, do it now (without dropping page lock) */ |
| 968 | dout(" page %p snapc %p not current, but oldest\n", |
| 969 | page, snapc); |
| 970 | if (!clear_page_dirty_for_io(page)) |
| 971 | goto retry_locked; |
| 972 | r = writepage_nounlock(page, NULL); |
| 973 | if (r < 0) |
| 974 | goto fail_nosnap; |
| 975 | goto retry_locked; |
| 976 | } |
| 977 | |
| 978 | if (PageUptodate(page)) { |
| 979 | dout(" page %p already uptodate\n", page); |
| 980 | return 0; |
| 981 | } |
| 982 | |
| 983 | /* full page? */ |
| 984 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) |
| 985 | return 0; |
| 986 | |
| 987 | /* past end of file? */ |
| 988 | i_size = inode->i_size; /* caller holds i_mutex */ |
| 989 | |
| 990 | if (i_size + len > inode->i_sb->s_maxbytes) { |
| 991 | /* file is too big */ |
| 992 | r = -EINVAL; |
| 993 | goto fail; |
| 994 | } |
| 995 | |
| 996 | if (page_off >= i_size || |
| 997 | (pos_in_page == 0 && (pos+len) >= i_size && |
| 998 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { |
| 999 | dout(" zeroing %p 0 - %d and %d - %d\n", |
| 1000 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); |
| 1001 | zero_user_segments(page, |
| 1002 | 0, pos_in_page, |
| 1003 | end_in_page, PAGE_CACHE_SIZE); |
| 1004 | return 0; |
| 1005 | } |
| 1006 | |
| 1007 | /* we need to read it. */ |
| 1008 | up_read(&mdsc->snap_rwsem); |
| 1009 | r = readpage_nounlock(file, page); |
| 1010 | if (r < 0) |
| 1011 | goto fail_nosnap; |
| 1012 | goto retry_locked; |
| 1013 | |
| 1014 | fail: |
| 1015 | up_read(&mdsc->snap_rwsem); |
| 1016 | fail_nosnap: |
| 1017 | unlock_page(page); |
| 1018 | return r; |
| 1019 | } |
| 1020 | |
| 1021 | /* |
| 1022 | * we don't do anything in here that simple_write_end doesn't do |
| 1023 | * except adjust dirty page accounting and drop read lock on |
| 1024 | * mdsc->snap_rwsem. |
| 1025 | */ |
| 1026 | static int ceph_write_end(struct file *file, struct address_space *mapping, |
| 1027 | loff_t pos, unsigned len, unsigned copied, |
| 1028 | struct page *page, void *fsdata) |
| 1029 | { |
| 1030 | struct inode *inode = file->f_dentry->d_inode; |
Yehuda Sadeh | 2baba25 | 2009-12-18 13:51:57 -0800 | [diff] [blame] | 1031 | struct ceph_client *client = ceph_inode_to_client(inode); |
| 1032 | struct ceph_mds_client *mdsc = &client->mdsc; |
Sage Weil | 1d3576f | 2009-10-06 11:31:09 -0700 | [diff] [blame] | 1033 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| 1034 | int check_cap = 0; |
| 1035 | |
| 1036 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, |
| 1037 | inode, page, (int)pos, (int)copied, (int)len); |
| 1038 | |
| 1039 | /* zero the stale part of the page if we did a short copy */ |
| 1040 | if (copied < len) |
| 1041 | zero_user_segment(page, from+copied, len); |
| 1042 | |
| 1043 | /* did file size increase? */ |
| 1044 | /* (no need for i_size_read(); we caller holds i_mutex */ |
| 1045 | if (pos+copied > inode->i_size) |
| 1046 | check_cap = ceph_inode_set_size(inode, pos+copied); |
| 1047 | |
| 1048 | if (!PageUptodate(page)) |
| 1049 | SetPageUptodate(page); |
| 1050 | |
| 1051 | set_page_dirty(page); |
| 1052 | |
| 1053 | unlock_page(page); |
| 1054 | up_read(&mdsc->snap_rwsem); |
| 1055 | page_cache_release(page); |
| 1056 | |
| 1057 | if (check_cap) |
| 1058 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); |
| 1059 | |
| 1060 | return copied; |
| 1061 | } |
| 1062 | |
| 1063 | /* |
| 1064 | * we set .direct_IO to indicate direct io is supported, but since we |
| 1065 | * intercept O_DIRECT reads and writes early, this function should |
| 1066 | * never get called. |
| 1067 | */ |
| 1068 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, |
| 1069 | const struct iovec *iov, |
| 1070 | loff_t pos, unsigned long nr_segs) |
| 1071 | { |
| 1072 | WARN_ON(1); |
| 1073 | return -EINVAL; |
| 1074 | } |
| 1075 | |
| 1076 | const struct address_space_operations ceph_aops = { |
| 1077 | .readpage = ceph_readpage, |
| 1078 | .readpages = ceph_readpages, |
| 1079 | .writepage = ceph_writepage, |
| 1080 | .writepages = ceph_writepages_start, |
| 1081 | .write_begin = ceph_write_begin, |
| 1082 | .write_end = ceph_write_end, |
| 1083 | .set_page_dirty = ceph_set_page_dirty, |
| 1084 | .invalidatepage = ceph_invalidatepage, |
| 1085 | .releasepage = ceph_releasepage, |
| 1086 | .direct_IO = ceph_direct_io, |
| 1087 | }; |
| 1088 | |
| 1089 | |
| 1090 | /* |
| 1091 | * vm ops |
| 1092 | */ |
| 1093 | |
| 1094 | /* |
| 1095 | * Reuse write_begin here for simplicity. |
| 1096 | */ |
| 1097 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 1098 | { |
| 1099 | struct inode *inode = vma->vm_file->f_dentry->d_inode; |
| 1100 | struct page *page = vmf->page; |
| 1101 | struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; |
| 1102 | loff_t off = page->index << PAGE_CACHE_SHIFT; |
| 1103 | loff_t size, len; |
| 1104 | struct page *locked_page = NULL; |
| 1105 | void *fsdata = NULL; |
| 1106 | int ret; |
| 1107 | |
| 1108 | size = i_size_read(inode); |
| 1109 | if (off + PAGE_CACHE_SIZE <= size) |
| 1110 | len = PAGE_CACHE_SIZE; |
| 1111 | else |
| 1112 | len = size & ~PAGE_CACHE_MASK; |
| 1113 | |
| 1114 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, |
| 1115 | off, len, page, page->index); |
| 1116 | ret = ceph_write_begin(vma->vm_file, inode->i_mapping, off, len, 0, |
| 1117 | &locked_page, &fsdata); |
| 1118 | WARN_ON(page != locked_page); |
| 1119 | if (!ret) { |
| 1120 | /* |
| 1121 | * doing the following, instead of calling |
| 1122 | * ceph_write_end. Note that we keep the |
| 1123 | * page locked |
| 1124 | */ |
| 1125 | set_page_dirty(page); |
| 1126 | up_read(&mdsc->snap_rwsem); |
| 1127 | page_cache_release(page); |
| 1128 | ret = VM_FAULT_LOCKED; |
| 1129 | } else { |
| 1130 | ret = VM_FAULT_SIGBUS; |
| 1131 | } |
| 1132 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
| 1133 | return ret; |
| 1134 | } |
| 1135 | |
| 1136 | static struct vm_operations_struct ceph_vmops = { |
| 1137 | .fault = filemap_fault, |
| 1138 | .page_mkwrite = ceph_page_mkwrite, |
| 1139 | }; |
| 1140 | |
| 1141 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) |
| 1142 | { |
| 1143 | struct address_space *mapping = file->f_mapping; |
| 1144 | |
| 1145 | if (!mapping->a_ops->readpage) |
| 1146 | return -ENOEXEC; |
| 1147 | file_accessed(file); |
| 1148 | vma->vm_ops = &ceph_vmops; |
| 1149 | vma->vm_flags |= VM_CAN_NONLINEAR; |
| 1150 | return 0; |
| 1151 | } |