fs/ceph/addr.c

   1 #include <linux/ceph/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/slab.h>
   9 #include <linux/pagevec.h>
  10 #include <linux/task_io_accounting_ops.h>
  11
  12 #include "super.h"
  13 #include "mds_client.h"
  14 #include "cache.h"
  15 #include <linux/ceph/osd_client.h>
  16
  17 /*
  18  * Ceph address space ops.
  19  *
  20  * There are a few funny things going on here.
  21  *
  22  * The page->private field is used to reference a struct
  23  * ceph_snap_context for _every_ dirty page.  This indicates which
  24  * snapshot the page was logically dirtied in, and thus which snap
  25  * context needs to be associated with the osd write during writeback.
  26  *
  27  * Similarly, struct ceph_inode_info maintains a set of counters to
  28  * count dirty pages on the inode.  In the absence of snapshots,
  29  * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
  30  *
  31  * When a snapshot is taken (that is, when the client receives
  32  * notification that a snapshot was taken), each inode with caps and
  33  * with dirty pages (dirty pages implies there is a cap) gets a new
  34  * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
  35  * order, new snaps go to the tail).  The i_wrbuffer_ref_head count is
  36  * moved to capsnap->dirty. (Unless a sync write is currently in
  37  * progress.  In that case, the capsnap is said to be "pending", new
  38  * writes cannot start, and the capsnap isn't "finalized" until the
  39  * write completes (or fails) and a final size/mtime for the inode for
  40  * that snap can be settled upon.)  i_wrbuffer_ref_head is reset to 0.
  41  *
  42  * On writeback, we must submit writes to the osd IN SNAP ORDER.  So,
  43  * we look for the first capsnap in i_cap_snaps and write out pages in
  44  * that snap context _only_.  Then we move on to the next capsnap,
  45  * eventually reaching the "live" or "head" context (i.e., pages that
  46  * are not yet snapped) and are writing the most recently dirtied
  47  * pages.
  48  *
  49  * Invalidate and so forth must take care to ensure the dirty page
  50  * accounting is preserved.
  51  */
  52
  53 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
  54 #define CONGESTION_OFF_THRESH(congestion_kb)                            \
  55         (CONGESTION_ON_THRESH(congestion_kb) -                          \
  56          (CONGESTION_ON_THRESH(congestion_kb) >> 2))
  57
  58 static inline struct ceph_snap_context *page_snap_context(struct page *page)
  59 {
  60         if (PagePrivate(page))
  61                 return (void *)page->private;
  62         return NULL;
  63 }
  64
  65 /*
  66  * Dirty a page.  Optimistically adjust accounting, on the assumption
  67  * that we won't race with invalidate.  If we do, readjust.
  68  */
  69 static int ceph_set_page_dirty(struct page *page)
  70 {
  71         struct address_space *mapping = page->mapping;
  72         struct inode *inode;
  73         struct ceph_inode_info *ci;
  74         struct ceph_snap_context *snapc;
  75         int ret;
  76
  77         if (unlikely(!mapping))
  78                 return !TestSetPageDirty(page);
  79
  80         if (PageDirty(page)) {
  81                 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
  82                      mapping->host, page, page->index);
  83                 BUG_ON(!PagePrivate(page));
  84                 return 0;
  85         }
  86
  87         inode = mapping->host;
  88         ci = ceph_inode(inode);
  89
  90         /* dirty the head */
  91         spin_lock(&ci->i_ceph_lock);
  92         BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
  93         if (__ceph_have_pending_cap_snap(ci)) {
  94                 struct ceph_cap_snap *capsnap =
  95                                 list_last_entry(&ci->i_cap_snaps,
  96                                                 struct ceph_cap_snap,
  97                                                 ci_item);
  98                 snapc = ceph_get_snap_context(capsnap->context);
  99                 capsnap->dirty_pages++;
 100         } else {
 101                 BUG_ON(!ci->i_head_snapc);
 102                 snapc = ceph_get_snap_context(ci->i_head_snapc);
 103                 ++ci->i_wrbuffer_ref_head;
 104         }
 105         if (ci->i_wrbuffer_ref == 0)
 106                 ihold(inode);
 107         ++ci->i_wrbuffer_ref;
 108         dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
 109              "snapc %p seq %lld (%d snaps)\n",
 110              mapping->host, page, page->index,
 111              ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
 112              ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
 113              snapc, snapc->seq, snapc->num_snaps);
 114         spin_unlock(&ci->i_ceph_lock);
 115
 116         /*
 117          * Reference snap context in page->private.  Also set
 118          * PagePrivate so that we get invalidatepage callback.
 119          */
 120         BUG_ON(PagePrivate(page));
 121         page->private = (unsigned long)snapc;
 122         SetPagePrivate(page);
 123
 124         ret = __set_page_dirty_nobuffers(page);
 125         WARN_ON(!PageLocked(page));
 126         WARN_ON(!page->mapping);
 127
 128         return ret;
 129 }
 130
 131 /*
 132  * If we are truncating the full page (i.e. offset == 0), adjust the
 133  * dirty page counters appropriately.  Only called if there is private
 134  * data on the page.
 135  */
 136 static void ceph_invalidatepage(struct page *page, unsigned int offset,
 137                                 unsigned int length)
 138 {
 139         struct inode *inode;
 140         struct ceph_inode_info *ci;
 141         struct ceph_snap_context *snapc = page_snap_context(page);
 142
 143         inode = page->mapping->host;
 144         ci = ceph_inode(inode);
 145
 146         if (offset != 0 || length != PAGE_CACHE_SIZE) {
 147                 dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
 148                      inode, page, page->index, offset, length);
 149                 return;
 150         }
 151
 152         ceph_invalidate_fscache_page(inode, page);
 153
 154         if (!PagePrivate(page))
 155                 return;
 156
 157         /*
 158          * We can get non-dirty pages here due to races between
 159          * set_page_dirty and truncate_complete_page; just spit out a
 160          * warning, in case we end up with accounting problems later.
 161          */
 162         if (!PageDirty(page))
 163                 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
 164
 165         ClearPageChecked(page);
 166
 167         dout("%p invalidatepage %p idx %lu full dirty page\n",
 168              inode, page, page->index);
 169
 170         ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 171         ceph_put_snap_context(snapc);
 172         page->private = 0;
 173         ClearPagePrivate(page);
 174 }
 175
 176 static int ceph_releasepage(struct page *page, gfp_t g)
 177 {
 178         struct inode *inode = page->mapping ? page->mapping->host : NULL;
 179         dout("%p releasepage %p idx %lu\n", inode, page, page->index);
 180         WARN_ON(PageDirty(page));
 181
 182         /* Can we release the page from the cache? */
 183         if (!ceph_release_fscache_page(page, g))
 184                 return 0;
 185
 186         return !PagePrivate(page);
 187 }
 188
 189 /*
 190  * read a single page, without unlocking it.
 191  */
 192 static int readpage_nounlock(struct file *filp, struct page *page)
 193 {
 194         struct inode *inode = file_inode(filp);
 195         struct ceph_inode_info *ci = ceph_inode(inode);
 196         struct ceph_osd_client *osdc =
 197                 &ceph_inode_to_client(inode)->client->osdc;
 198         int err = 0;
 199         u64 off = page_offset(page);
 200         u64 len = PAGE_CACHE_SIZE;
 201
 202         if (off >= i_size_read(inode)) {
 203                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 204                 SetPageUptodate(page);
 205                 return 0;
 206         }
 207
 208         if (ci->i_inline_version != CEPH_INLINE_NONE) {
 209                 /*
 210                  * Uptodate inline data should have been added
 211                  * into page cache while getting Fcr caps.
 212                  */
 213                 if (off == 0)
 214                         return -EINVAL;
 215                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 216                 SetPageUptodate(page);
 217                 return 0;
 218         }
 219
 220         err = ceph_readpage_from_fscache(inode, page);
 221         if (err == 0)
 222                 goto out;
 223
 224         dout("readpage inode %p file %p page %p index %lu\n",
 225              inode, filp, page, page->index);
 226         err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
 227                                   off, &len,
 228                                   ci->i_truncate_seq, ci->i_truncate_size,
 229                                   &page, 1, 0);
 230         if (err == -ENOENT)
 231                 err = 0;
 232         if (err < 0) {
 233                 SetPageError(page);
 234                 ceph_fscache_readpage_cancel(inode, page);
 235                 goto out;
 236         }
 237         if (err < PAGE_CACHE_SIZE)
 238                 /* zero fill remainder of page */
 239                 zero_user_segment(page, err, PAGE_CACHE_SIZE);
 240         else
 241                 flush_dcache_page(page);
 242
 243         SetPageUptodate(page);
 244         ceph_readpage_to_fscache(inode, page);
 245
 246 out:
 247         return err < 0 ? err : 0;
 248 }
 249
 250 static int ceph_readpage(struct file *filp, struct page *page)
 251 {
 252         int r = readpage_nounlock(filp, page);
 253         unlock_page(page);
 254         return r;
 255 }
 256
 257 /*
 258  * Finish an async read(ahead) op.
 259  */
 260 static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg)
 261 {
 262         struct inode *inode = req->r_inode;
 263         struct ceph_osd_data *osd_data;
 264         int rc = req->r_result;
 265         int bytes = le32_to_cpu(msg->hdr.data_len);
 266         int num_pages;
 267         int i;
 268
 269         dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
 270
 271         /* unlock all pages, zeroing any data we didn't read */
 272         osd_data = osd_req_op_extent_osd_data(req, 0);
 273         BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 274         num_pages = calc_pages_for((u64)osd_data->alignment,
 275                                         (u64)osd_data->length);
 276         for (i = 0; i < num_pages; i++) {
 277                 struct page *page = osd_data->pages[i];
 278
 279                 if (rc < 0)
 280                         goto unlock;
 281                 if (bytes < (int)PAGE_CACHE_SIZE) {
 282                         /* zero (remainder of) page */
 283                         int s = bytes < 0 ? 0 : bytes;
 284                         zero_user_segment(page, s, PAGE_CACHE_SIZE);
 285                 }
 286                 dout("finish_read %p uptodate %p idx %lu\n", inode, page,
 287                      page->index);
 288                 flush_dcache_page(page);
 289                 SetPageUptodate(page);
 290                 ceph_readpage_to_fscache(inode, page);
 291 unlock:
 292                 unlock_page(page);
 293                 page_cache_release(page);
 294                 bytes -= PAGE_CACHE_SIZE;
 295         }
 296         kfree(osd_data->pages);
 297 }
 298
 299 static void ceph_unlock_page_vector(struct page **pages, int num_pages)
 300 {
 301         int i;
 302
 303         for (i = 0; i < num_pages; i++)
 304                 unlock_page(pages[i]);
 305 }
 306
 307 /*
 308  * start an async read(ahead) operation.  return nr_pages we submitted
 309  * a read for on success, or negative error code.
 310  */
 311 static int start_read(struct inode *inode, struct list_head *page_list, int max)
 312 {
 313         struct ceph_osd_client *osdc =
 314                 &ceph_inode_to_client(inode)->client->osdc;
 315         struct ceph_inode_info *ci = ceph_inode(inode);
 316         struct page *page = list_entry(page_list->prev, struct page, lru);
 317         struct ceph_vino vino;
 318         struct ceph_osd_request *req;
 319         u64 off;
 320         u64 len;
 321         int i;
 322         struct page **pages;
 323         pgoff_t next_index;
 324         int nr_pages = 0;
 325         int ret;
 326
 327         off = (u64) page_offset(page);
 328
 329         /* count pages */
 330         next_index = page->index;
 331         list_for_each_entry_reverse(page, page_list, lru) {
 332                 if (page->index != next_index)
 333                         break;
 334                 nr_pages++;
 335                 next_index++;
 336                 if (max && nr_pages == max)
 337                         break;
 338         }
 339         len = nr_pages << PAGE_CACHE_SHIFT;
 340         dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
 341              off, len);
 342         vino = ceph_vino(inode);
 343         req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
 344                                     0, 1, CEPH_OSD_OP_READ,
 345                                     CEPH_OSD_FLAG_READ, NULL,
 346                                     ci->i_truncate_seq, ci->i_truncate_size,
 347                                     false);
 348         if (IS_ERR(req))
 349                 return PTR_ERR(req);
 350
 351         /* build page vector */
 352         nr_pages = calc_pages_for(0, len);
 353         pages = kmalloc(sizeof(*pages) * nr_pages, GFP_KERNEL);
 354         ret = -ENOMEM;
 355         if (!pages)
 356                 goto out;
 357         for (i = 0; i < nr_pages; ++i) {
 358                 page = list_entry(page_list->prev, struct page, lru);
 359                 BUG_ON(PageLocked(page));
 360                 list_del(&page->lru);
 361
 362                 dout("start_read %p adding %p idx %lu\n", inode, page,
 363                      page->index);
 364                 if (add_to_page_cache_lru(page, &inode->i_data, page->index,
 365                                           GFP_KERNEL)) {
 366                         ceph_fscache_uncache_page(inode, page);
 367                         page_cache_release(page);
 368                         dout("start_read %p add_to_page_cache failed %p\n",
 369                              inode, page);
 370                         nr_pages = i;
 371                         goto out_pages;
 372                 }
 373                 pages[i] = page;
 374         }
 375         osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
 376         req->r_callback = finish_read;
 377         req->r_inode = inode;
 378
 379         ceph_osdc_build_request(req, off, NULL, vino.snap, NULL);
 380
 381         dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
 382         ret = ceph_osdc_start_request(osdc, req, false);
 383         if (ret < 0)
 384                 goto out_pages;
 385         ceph_osdc_put_request(req);
 386         return nr_pages;
 387
 388 out_pages:
 389         ceph_unlock_page_vector(pages, nr_pages);
 390         ceph_release_page_vector(pages, nr_pages);
 391 out:
 392         ceph_osdc_put_request(req);
 393         return ret;
 394 }
 395
 396
 397 /*
 398  * Read multiple pages.  Leave pages we don't read + unlock in page_list;
 399  * the caller (VM) cleans them up.
 400  */
 401 static int ceph_readpages(struct file *file, struct address_space *mapping,
 402                           struct list_head *page_list, unsigned nr_pages)
 403 {
 404         struct inode *inode = file_inode(file);
 405         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 406         int rc = 0;
 407         int max = 0;
 408
 409         if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
 410                 return -EINVAL;
 411
 412         rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
 413                                          &nr_pages);
 414
 415         if (rc == 0)
 416                 goto out;
 417
 418         if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
 419                 max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
 420                         >> PAGE_SHIFT;
 421
 422         dout("readpages %p file %p nr_pages %d max %d\n", inode,
 423                 file, nr_pages,
 424              max);
 425         while (!list_empty(page_list)) {
 426                 rc = start_read(inode, page_list, max);
 427                 if (rc < 0)
 428                         goto out;
 429                 BUG_ON(rc == 0);
 430         }
 431 out:
 432         ceph_fscache_readpages_cancel(inode, page_list);
 433
 434         dout("readpages %p file %p ret %d\n", inode, file, rc);
 435         return rc;
 436 }
 437
 438 /*
 439  * Get ref for the oldest snapc for an inode with dirty data... that is, the
 440  * only snap context we are allowed to write back.
 441  */
 442 static struct ceph_snap_context *get_oldest_context(struct inode *inode,
 443                                                     loff_t *snap_size)
 444 {
 445         struct ceph_inode_info *ci = ceph_inode(inode);
 446         struct ceph_snap_context *snapc = NULL;
 447         struct ceph_cap_snap *capsnap = NULL;
 448
 449         spin_lock(&ci->i_ceph_lock);
 450         list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 451                 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
 452                      capsnap->context, capsnap->dirty_pages);
 453                 if (capsnap->dirty_pages) {
 454                         snapc = ceph_get_snap_context(capsnap->context);
 455                         if (snap_size)
 456                                 *snap_size = capsnap->size;
 457                         break;
 458                 }
 459         }
 460         if (!snapc && ci->i_wrbuffer_ref_head) {
 461                 snapc = ceph_get_snap_context(ci->i_head_snapc);
 462                 dout(" head snapc %p has %d dirty pages\n",
 463                      snapc, ci->i_wrbuffer_ref_head);
 464         }
 465         spin_unlock(&ci->i_ceph_lock);
 466         return snapc;
 467 }
 468
 469 /*
 470  * Write a single page, but leave the page locked.
 471  *
 472  * If we get a write error, set the page error bit, but still adjust the
 473  * dirty page accounting (i.e., page is no longer dirty).
 474  */
 475 static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 476 {
 477         struct inode *inode;
 478         struct ceph_inode_info *ci;
 479         struct ceph_fs_client *fsc;
 480         struct ceph_osd_client *osdc;
 481         struct ceph_snap_context *snapc, *oldest;
 482         loff_t page_off = page_offset(page);
 483         loff_t snap_size = -1;
 484         long writeback_stat;
 485         u64 truncate_size;
 486         u32 truncate_seq;
 487         int err = 0, len = PAGE_CACHE_SIZE;
 488
 489         dout("writepage %p idx %lu\n", page, page->index);
 490
 491         if (!page->mapping || !page->mapping->host) {
 492                 dout("writepage %p - no mapping\n", page);
 493                 return -EFAULT;
 494         }
 495         inode = page->mapping->host;
 496         ci = ceph_inode(inode);
 497         fsc = ceph_inode_to_client(inode);
 498         osdc = &fsc->client->osdc;
 499
 500         /* verify this is a writeable snap context */
 501         snapc = page_snap_context(page);
 502         if (snapc == NULL) {
 503                 dout("writepage %p page %p not dirty?\n", inode, page);
 504                 goto out;
 505         }
 506         oldest = get_oldest_context(inode, &snap_size);
 507         if (snapc->seq > oldest->seq) {
 508                 dout("writepage %p page %p snapc %p not writeable - noop\n",
 509                      inode, page, snapc);
 510                 /* we should only noop if called by kswapd */
 511                 WARN_ON((current->flags & PF_MEMALLOC) == 0);
 512                 ceph_put_snap_context(oldest);
 513                 goto out;
 514         }
 515         ceph_put_snap_context(oldest);
 516
 517         spin_lock(&ci->i_ceph_lock);
 518         truncate_seq = ci->i_truncate_seq;
 519         truncate_size = ci->i_truncate_size;
 520         if (snap_size == -1)
 521                 snap_size = i_size_read(inode);
 522         spin_unlock(&ci->i_ceph_lock);
 523
 524         /* is this a partial page at end of file? */
 525         if (page_off >= snap_size) {
 526                 dout("%p page eof %llu\n", page, snap_size);
 527                 goto out;
 528         }
 529         if (snap_size < page_off + len)
 530                 len = snap_size - page_off;
 531
 532         dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
 533              inode, page, page->index, page_off, len, snapc);
 534
 535         writeback_stat = atomic_long_inc_return(&fsc->writeback_count);
 536         if (writeback_stat >
 537             CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
 538                 set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
 539
 540         ceph_readpage_to_fscache(inode, page);
 541
 542         set_page_writeback(page);
 543         err = ceph_osdc_writepages(osdc, ceph_vino(inode),
 544                                    &ci->i_layout, snapc,
 545                                    page_off, len,
 546                                    truncate_seq, truncate_size,
 547                                    &inode->i_mtime, &page, 1);
 548         if (err < 0) {
 549                 dout("writepage setting page/mapping error %d %p\n", err, page);
 550                 SetPageError(page);
 551                 mapping_set_error(&inode->i_data, err);
 552                 if (wbc)
 553                         wbc->pages_skipped++;
 554         } else {
 555                 dout("writepage cleaned page %p\n", page);
 556                 err = 0;  /* vfs expects us to return 0 */
 557         }
 558         page->private = 0;
 559         ClearPagePrivate(page);
 560         end_page_writeback(page);
 561         ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 562         ceph_put_snap_context(snapc);  /* page's reference */
 563 out:
 564         return err;
 565 }
 566
 567 static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 568 {
 569         int err;
 570         struct inode *inode = page->mapping->host;
 571         BUG_ON(!inode);
 572         ihold(inode);
 573         err = writepage_nounlock(page, wbc);
 574         unlock_page(page);
 575         iput(inode);
 576         return err;
 577 }
 578
 579
 580 /*
 581  * lame release_pages helper.  release_pages() isn't exported to
 582  * modules.
 583  */
 584 static void ceph_release_pages(struct page **pages, int num)
 585 {
 586         struct pagevec pvec;
 587         int i;
 588
 589         pagevec_init(&pvec, 0);
 590         for (i = 0; i < num; i++) {
 591                 if (pagevec_add(&pvec, pages[i]) == 0)
 592                         pagevec_release(&pvec);
 593         }
 594         pagevec_release(&pvec);
 595 }
 596
 597 /*
 598  * async writeback completion handler.
 599  *
 600  * If we get an error, set the mapping error bit, but not the individual
 601  * page error bits.
 602  */
 603 static void writepages_finish(struct ceph_osd_request *req,
 604                               struct ceph_msg *msg)
 605 {
 606         struct inode *inode = req->r_inode;
 607         struct ceph_inode_info *ci = ceph_inode(inode);
 608         struct ceph_osd_data *osd_data;
 609         unsigned wrote;
 610         struct page *page;
 611         int num_pages;
 612         int i;
 613         struct ceph_snap_context *snapc = req->r_snapc;
 614         struct address_space *mapping = inode->i_mapping;
 615         int rc = req->r_result;
 616         u64 bytes = req->r_ops[0].extent.length;
 617         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 618         long writeback_stat;
 619         unsigned issued = ceph_caps_issued(ci);
 620
 621         osd_data = osd_req_op_extent_osd_data(req, 0);
 622         BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 623         num_pages = calc_pages_for((u64)osd_data->alignment,
 624                                         (u64)osd_data->length);
 625         if (rc >= 0) {
 626                 /*
 627                  * Assume we wrote the pages we originally sent.  The
 628                  * osd might reply with fewer pages if our writeback
 629                  * raced with a truncation and was adjusted at the osd,
 630                  * so don't believe the reply.
 631                  */
 632                 wrote = num_pages;
 633         } else {
 634                 wrote = 0;
 635                 mapping_set_error(mapping, rc);
 636         }
 637         dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
 638              inode, rc, bytes, wrote);
 639
 640         /* clean all pages */
 641         for (i = 0; i < num_pages; i++) {
 642                 page = osd_data->pages[i];
 643                 BUG_ON(!page);
 644                 WARN_ON(!PageUptodate(page));
 645
 646                 writeback_stat =
 647                         atomic_long_dec_return(&fsc->writeback_count);
 648                 if (writeback_stat <
 649                     CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
 650                         clear_bdi_congested(&fsc->backing_dev_info,
 651                                             BLK_RW_ASYNC);
 652
 653                 ceph_put_snap_context(page_snap_context(page));
 654                 page->private = 0;
 655                 ClearPagePrivate(page);
 656                 dout("unlocking %d %p\n", i, page);
 657                 end_page_writeback(page);
 658
 659                 /*
 660                  * We lost the cache cap, need to truncate the page before
 661                  * it is unlocked, otherwise we'd truncate it later in the
 662                  * page truncation thread, possibly losing some data that
 663                  * raced its way in
 664                  */
 665                 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
 666                         generic_error_remove_page(inode->i_mapping, page);
 667
 668                 unlock_page(page);
 669         }
 670         dout("%p wrote+cleaned %d pages\n", inode, wrote);
 671         ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc);
 672
 673         ceph_release_pages(osd_data->pages, num_pages);
 674         if (osd_data->pages_from_pool)
 675                 mempool_free(osd_data->pages,
 676                              ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
 677         else
 678                 kfree(osd_data->pages);
 679         ceph_osdc_put_request(req);
 680 }
 681
 682 /*
 683  * initiate async writeback
 684  */
 685 static int ceph_writepages_start(struct address_space *mapping,
 686                                  struct writeback_control *wbc)
 687 {
 688         struct inode *inode = mapping->host;
 689         struct ceph_inode_info *ci = ceph_inode(inode);
 690         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 691         struct ceph_vino vino = ceph_vino(inode);
 692         pgoff_t index, start, end;
 693         int range_whole = 0;
 694         int should_loop = 1;
 695         pgoff_t max_pages = 0, max_pages_ever = 0;
 696         struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
 697         struct pagevec pvec;
 698         int done = 0;
 699         int rc = 0;
 700         unsigned wsize = 1 << inode->i_blkbits;
 701         struct ceph_osd_request *req = NULL;
 702         int do_sync = 0;
 703         loff_t snap_size, i_size;
 704         u64 truncate_size;
 705         u32 truncate_seq;
 706
 707         /*
 708          * Include a 'sync' in the OSD request if this is a data
 709          * integrity write (e.g., O_SYNC write or fsync()), or if our
 710          * cap is being revoked.
 711          */
 712         if ((wbc->sync_mode == WB_SYNC_ALL) ||
 713                 ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
 714                 do_sync = 1;
 715         dout("writepages_start %p dosync=%d (mode=%s)\n",
 716              inode, do_sync,
 717              wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
 718              (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
 719
 720         if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) {
 721                 pr_warn("writepage_start %p on forced umount\n", inode);
 722                 return -EIO; /* we're in a forced umount, don't write! */
 723         }
 724         if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
 725                 wsize = fsc->mount_options->wsize;
 726         if (wsize < PAGE_CACHE_SIZE)
 727                 wsize = PAGE_CACHE_SIZE;
 728         max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
 729
 730         pagevec_init(&pvec, 0);
 731
 732         /* where to start/end? */
 733         if (wbc->range_cyclic) {
 734                 start = mapping->writeback_index; /* Start from prev offset */
 735                 end = -1;
 736                 dout(" cyclic, start at %lu\n", start);
 737         } else {
 738                 start = wbc->range_start >> PAGE_CACHE_SHIFT;
 739                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
 740                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 741                         range_whole = 1;
 742                 should_loop = 0;
 743                 dout(" not cyclic, %lu to %lu\n", start, end);
 744         }
 745         index = start;
 746
 747 retry:
 748         /* find oldest snap context with dirty data */
 749         ceph_put_snap_context(snapc);
 750         snap_size = -1;
 751         snapc = get_oldest_context(inode, &snap_size);
 752         if (!snapc) {
 753                 /* hmm, why does writepages get called when there
 754                    is no dirty data? */
 755                 dout(" no snap context with dirty data?\n");
 756                 goto out;
 757         }
 758         dout(" oldest snapc is %p seq %lld (%d snaps)\n",
 759              snapc, snapc->seq, snapc->num_snaps);
 760
 761         spin_lock(&ci->i_ceph_lock);
 762         truncate_seq = ci->i_truncate_seq;
 763         truncate_size = ci->i_truncate_size;
 764         i_size = i_size_read(inode);
 765         spin_unlock(&ci->i_ceph_lock);
 766
 767         if (last_snapc && snapc != last_snapc) {
 768                 /* if we switched to a newer snapc, restart our scan at the
 769                  * start of the original file range. */
 770                 dout("  snapc differs from last pass, restarting at %lu\n",
 771                      index);
 772                 index = start;
 773         }
 774         last_snapc = snapc;
 775
 776         while (!done && index <= end) {
 777                 unsigned i;
 778                 int first;
 779                 pgoff_t next;
 780                 int pvec_pages, locked_pages;
 781                 struct page **pages = NULL;
 782                 mempool_t *pool = NULL; /* Becomes non-null if mempool used */
 783                 struct page *page;
 784                 int want;
 785                 u64 offset, len;
 786                 long writeback_stat;
 787
 788                 next = 0;
 789                 locked_pages = 0;
 790                 max_pages = max_pages_ever;
 791
 792 get_more_pages:
 793                 first = -1;
 794                 want = min(end - index,
 795                            min((pgoff_t)PAGEVEC_SIZE,
 796                                max_pages - (pgoff_t)locked_pages) - 1)
 797                         + 1;
 798                 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
 799                                                 PAGECACHE_TAG_DIRTY,
 800                                                 want);
 801                 dout("pagevec_lookup_tag got %d\n", pvec_pages);
 802                 if (!pvec_pages && !locked_pages)
 803                         break;
 804                 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
 805                         page = pvec.pages[i];
 806                         dout("? %p idx %lu\n", page, page->index);
 807                         if (locked_pages == 0)
 808                                 lock_page(page);  /* first page */
 809                         else if (!trylock_page(page))
 810                                 break;
 811
 812                         /* only dirty pages, or our accounting breaks */
 813                         if (unlikely(!PageDirty(page)) ||
 814                             unlikely(page->mapping != mapping)) {
 815                                 dout("!dirty or !mapping %p\n", page);
 816                                 unlock_page(page);
 817                                 break;
 818                         }
 819                         if (!wbc->range_cyclic && page->index > end) {
 820                                 dout("end of range %p\n", page);
 821                                 done = 1;
 822                                 unlock_page(page);
 823                                 break;
 824                         }
 825                         if (next && (page->index != next)) {
 826                                 dout("not consecutive %p\n", page);
 827                                 unlock_page(page);
 828                                 break;
 829                         }
 830                         if (wbc->sync_mode != WB_SYNC_NONE) {
 831                                 dout("waiting on writeback %p\n", page);
 832                                 wait_on_page_writeback(page);
 833                         }
 834                         if (page_offset(page) >=
 835                             (snap_size == -1 ? i_size : snap_size)) {
 836                                 dout("%p page eof %llu\n", page,
 837                                      (snap_size == -1 ? i_size : snap_size));
 838                                 done = 1;
 839                                 unlock_page(page);
 840                                 break;
 841                         }
 842                         if (PageWriteback(page)) {
 843                                 dout("%p under writeback\n", page);
 844                                 unlock_page(page);
 845                                 break;
 846                         }
 847
 848                         /* only if matching snap context */
 849                         pgsnapc = page_snap_context(page);
 850                         if (pgsnapc->seq > snapc->seq) {
 851                                 dout("page snapc %p %lld > oldest %p %lld\n",
 852                                      pgsnapc, pgsnapc->seq, snapc, snapc->seq);
 853                                 unlock_page(page);
 854                                 if (!locked_pages)
 855                                         continue; /* keep looking for snap */
 856                                 break;
 857                         }
 858
 859                         if (!clear_page_dirty_for_io(page)) {
 860                                 dout("%p !clear_page_dirty_for_io\n", page);
 861                                 unlock_page(page);
 862                                 break;
 863                         }
 864
 865                         /*
 866                          * We have something to write.  If this is
 867                          * the first locked page this time through,
 868                          * allocate an osd request and a page array
 869                          * that it will use.
 870                          */
 871                         if (locked_pages == 0) {
 872                                 BUG_ON(pages);
 873                                 /* prepare async write request */
 874                                 offset = (u64)page_offset(page);
 875                                 len = wsize;
 876                                 req = ceph_osdc_new_request(&fsc->client->osdc,
 877                                                         &ci->i_layout, vino,
 878                                                         offset, &len, 0,
 879                                                         do_sync ? 2 : 1,
 880                                                         CEPH_OSD_OP_WRITE,
 881                                                         CEPH_OSD_FLAG_WRITE |
 882                                                         CEPH_OSD_FLAG_ONDISK,
 883                                                         snapc, truncate_seq,
 884                                                         truncate_size, true);
 885                                 if (IS_ERR(req)) {
 886                                         rc = PTR_ERR(req);
 887                                         unlock_page(page);
 888                                         break;
 889                                 }
 890
 891                                 if (do_sync)
 892                                         osd_req_op_init(req, 1,
 893                                                         CEPH_OSD_OP_STARTSYNC, 0);
 894
 895                                 req->r_callback = writepages_finish;
 896                                 req->r_inode = inode;
 897
 898                                 max_pages = calc_pages_for(0, (u64)len);
 899                                 pages = kmalloc(max_pages * sizeof (*pages),
 900                                                 GFP_NOFS);
 901                                 if (!pages) {
 902                                         pool = fsc->wb_pagevec_pool;
 903                                         pages = mempool_alloc(pool, GFP_NOFS);
 904                                         BUG_ON(!pages);
 905                                 }
 906                         }
 907
 908                         /* note position of first page in pvec */
 909                         if (first < 0)
 910                                 first = i;
 911                         dout("%p will write page %p idx %lu\n",
 912                              inode, page, page->index);
 913
 914                         writeback_stat =
 915                                atomic_long_inc_return(&fsc->writeback_count);
 916                         if (writeback_stat > CONGESTION_ON_THRESH(
 917                                     fsc->mount_options->congestion_kb)) {
 918                                 set_bdi_congested(&fsc->backing_dev_info,
 919                                                   BLK_RW_ASYNC);
 920                         }
 921
 922                         set_page_writeback(page);
 923                         pages[locked_pages] = page;
 924                         locked_pages++;
 925                         next = page->index + 1;
 926                 }
 927
 928                 /* did we get anything? */
 929                 if (!locked_pages)
 930                         goto release_pvec_pages;
 931                 if (i) {
 932                         int j;
 933                         BUG_ON(!locked_pages || first < 0);
 934
 935                         if (pvec_pages && i == pvec_pages &&
 936                             locked_pages < max_pages) {
 937                                 dout("reached end pvec, trying for more\n");
 938                                 pagevec_reinit(&pvec);
 939                                 goto get_more_pages;
 940                         }
 941
 942                         /* shift unused pages over in the pvec...  we
 943                          * will need to release them below. */
 944                         for (j = i; j < pvec_pages; j++) {
 945                                 dout(" pvec leftover page %p\n",
 946                                      pvec.pages[j]);
 947                                 pvec.pages[j-i+first] = pvec.pages[j];
 948                         }
 949                         pvec.nr -= i-first;
 950                 }
 951
 952                 /* Format the osd request message and submit the write */
 953                 offset = page_offset(pages[0]);
 954                 len = (u64)locked_pages << PAGE_CACHE_SHIFT;
 955                 if (snap_size == -1) {
 956                         len = min(len, (u64)i_size_read(inode) - offset);
 957                          /* writepages_finish() clears writeback pages
 958                           * according to the data length, so make sure
 959                           * data length covers all locked pages */
 960                         len = max(len, 1 +
 961                                 ((u64)(locked_pages - 1) << PAGE_CACHE_SHIFT));
 962                 } else {
 963                         len = min(len, snap_size - offset);
 964                 }
 965                 dout("writepages got %d pages at %llu~%llu\n",
 966                      locked_pages, offset, len);
 967
 968                 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
 969                                                         !!pool, false);
 970
 971                 pages = NULL;   /* request message now owns the pages array */
 972                 pool = NULL;
 973
 974                 /* Update the write op length in case we changed it */
 975
 976                 osd_req_op_extent_update(req, 0, len);
 977
 978                 vino = ceph_vino(inode);
 979                 ceph_osdc_build_request(req, offset, snapc, vino.snap,
 980                                         &inode->i_mtime);
 981
 982                 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
 983                 BUG_ON(rc);
 984                 req = NULL;
 985
 986                 /* continue? */
 987                 index = next;
 988                 wbc->nr_to_write -= locked_pages;
 989                 if (wbc->nr_to_write <= 0)
 990                         done = 1;
 991
 992 release_pvec_pages:
 993                 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
 994                      pvec.nr ? pvec.pages[0] : NULL);
 995                 pagevec_release(&pvec);
 996
 997                 if (locked_pages && !done)
 998                         goto retry;
 999         }
1000
1001         if (should_loop && !done) {
1002                 /* more to do; loop back to beginning of file */
1003                 dout("writepages looping back to beginning of file\n");
1004                 should_loop = 0;
1005                 index = 0;
1006                 goto retry;
1007         }
1008
1009         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1010                 mapping->writeback_index = index;
1011
1012 out:
1013         if (req)
1014                 ceph_osdc_put_request(req);
1015         ceph_put_snap_context(snapc);
1016         dout("writepages done, rc = %d\n", rc);
1017         return rc;
1018 }
1019
1020
1021
1022 /*
1023  * See if a given @snapc is either writeable, or already written.
1024  */
1025 static int context_is_writeable_or_written(struct inode *inode,
1026                                            struct ceph_snap_context *snapc)
1027 {
1028         struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
1029         int ret = !oldest || snapc->seq <= oldest->seq;
1030
1031         ceph_put_snap_context(oldest);
1032         return ret;
1033 }
1034
1035 /*
1036  * We are only allowed to write into/dirty the page if the page is
1037  * clean, or already dirty within the same snap context.
1038  *
1039  * called with page locked.
1040  * return success with page locked,
1041  * or any failure (incl -EAGAIN) with page unlocked.
1042  */
1043 static int ceph_update_writeable_page(struct file *file,
1044                             loff_t pos, unsigned len,
1045                             struct page *page)
1046 {
1047         struct inode *inode = file_inode(file);
1048         struct ceph_inode_info *ci = ceph_inode(inode);
1049         loff_t page_off = pos & PAGE_CACHE_MASK;
1050         int pos_in_page = pos & ~PAGE_CACHE_MASK;
1051         int end_in_page = pos_in_page + len;
1052         loff_t i_size;
1053         int r;
1054         struct ceph_snap_context *snapc, *oldest;
1055
1056 retry_locked:
1057         /* writepages currently holds page lock, but if we change that later, */
1058         wait_on_page_writeback(page);
1059
1060         snapc = page_snap_context(page);
1061         if (snapc && snapc != ci->i_head_snapc) {
1062                 /*
1063                  * this page is already dirty in another (older) snap
1064                  * context!  is it writeable now?
1065                  */
1066                 oldest = get_oldest_context(inode, NULL);
1067
1068                 if (snapc->seq > oldest->seq) {
1069                         ceph_put_snap_context(oldest);
1070                         dout(" page %p snapc %p not current or oldest\n",
1071                              page, snapc);
1072                         /*
1073                          * queue for writeback, and wait for snapc to
1074                          * be writeable or written
1075                          */
1076                         snapc = ceph_get_snap_context(snapc);
1077                         unlock_page(page);
1078                         ceph_queue_writeback(inode);
1079                         r = wait_event_interruptible(ci->i_cap_wq,
1080                                context_is_writeable_or_written(inode, snapc));
1081                         ceph_put_snap_context(snapc);
1082                         if (r == -ERESTARTSYS)
1083                                 return r;
1084                         return -EAGAIN;
1085                 }
1086                 ceph_put_snap_context(oldest);
1087
1088                 /* yay, writeable, do it now (without dropping page lock) */
1089                 dout(" page %p snapc %p not current, but oldest\n",
1090                      page, snapc);
1091                 if (!clear_page_dirty_for_io(page))
1092                         goto retry_locked;
1093                 r = writepage_nounlock(page, NULL);
1094                 if (r < 0)
1095                         goto fail_nosnap;
1096                 goto retry_locked;
1097         }
1098
1099         if (PageUptodate(page)) {
1100                 dout(" page %p already uptodate\n", page);
1101                 return 0;
1102         }
1103
1104         /* full page? */
1105         if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
1106                 return 0;
1107
1108         /* past end of file? */
1109         i_size = inode->i_size;   /* caller holds i_mutex */
1110
1111         if (page_off >= i_size ||
1112             (pos_in_page == 0 && (pos+len) >= i_size &&
1113              end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1114                 dout(" zeroing %p 0 - %d and %d - %d\n",
1115                      page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1116                 zero_user_segments(page,
1117                                    0, pos_in_page,
1118                                    end_in_page, PAGE_CACHE_SIZE);
1119                 return 0;
1120         }
1121
1122         /* we need to read it. */
1123         r = readpage_nounlock(file, page);
1124         if (r < 0)
1125                 goto fail_nosnap;
1126         goto retry_locked;
1127 fail_nosnap:
1128         unlock_page(page);
1129         return r;
1130 }
1131
1132 /*
1133  * We are only allowed to write into/dirty the page if the page is
1134  * clean, or already dirty within the same snap context.
1135  */
1136 static int ceph_write_begin(struct file *file, struct address_space *mapping,
1137                             loff_t pos, unsigned len, unsigned flags,
1138                             struct page **pagep, void **fsdata)
1139 {
1140         struct inode *inode = file_inode(file);
1141         struct page *page;
1142         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1143         int r;
1144
1145         do {
1146                 /* get a page */
1147                 page = grab_cache_page_write_begin(mapping, index, 0);
1148                 if (!page)
1149                         return -ENOMEM;
1150                 *pagep = page;
1151
1152                 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1153                      inode, page, (int)pos, (int)len);
1154
1155                 r = ceph_update_writeable_page(file, pos, len, page);
1156                 if (r < 0)
1157                         page_cache_release(page);
1158                 else
1159                         *pagep = page;
1160         } while (r == -EAGAIN);
1161
1162         return r;
1163 }
1164
1165 /*
1166  * we don't do anything in here that simple_write_end doesn't do
1167  * except adjust dirty page accounting
1168  */
1169 static int ceph_write_end(struct file *file, struct address_space *mapping,
1170                           loff_t pos, unsigned len, unsigned copied,
1171                           struct page *page, void *fsdata)
1172 {
1173         struct inode *inode = file_inode(file);
1174         unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1175         int check_cap = 0;
1176
1177         dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1178              inode, page, (int)pos, (int)copied, (int)len);
1179
1180         /* zero the stale part of the page if we did a short copy */
1181         if (copied < len)
1182                 zero_user_segment(page, from+copied, len);
1183
1184         /* did file size increase? */
1185         /* (no need for i_size_read(); we caller holds i_mutex */
1186         if (pos+copied > inode->i_size)
1187                 check_cap = ceph_inode_set_size(inode, pos+copied);
1188
1189         if (!PageUptodate(page))
1190                 SetPageUptodate(page);
1191
1192         set_page_dirty(page);
1193
1194         unlock_page(page);
1195         page_cache_release(page);
1196
1197         if (check_cap)
1198                 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1199
1200         return copied;
1201 }
1202
1203 /*
1204  * we set .direct_IO to indicate direct io is supported, but since we
1205  * intercept O_DIRECT reads and writes early, this function should
1206  * never get called.
1207  */
1208 static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter,
1209                               loff_t pos)
1210 {
1211         WARN_ON(1);
1212         return -EINVAL;
1213 }
1214
1215 const struct address_space_operations ceph_aops = {
1216         .readpage = ceph_readpage,
1217         .readpages = ceph_readpages,
1218         .writepage = ceph_writepage,
1219         .writepages = ceph_writepages_start,
1220         .write_begin = ceph_write_begin,
1221         .write_end = ceph_write_end,
1222         .set_page_dirty = ceph_set_page_dirty,
1223         .invalidatepage = ceph_invalidatepage,
1224         .releasepage = ceph_releasepage,
1225         .direct_IO = ceph_direct_io,
1226 };
1227
1228
1229 /*
1230  * vm ops
1231  */
1232 static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1233 {
1234         struct inode *inode = file_inode(vma->vm_file);
1235         struct ceph_inode_info *ci = ceph_inode(inode);
1236         struct ceph_file_info *fi = vma->vm_file->private_data;
1237         struct page *pinned_page = NULL;
1238         loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
1239         int want, got, ret;
1240
1241         dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1242              inode, ceph_vinop(inode), off, (size_t)PAGE_CACHE_SIZE);
1243         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1244                 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1245         else
1246                 want = CEPH_CAP_FILE_CACHE;
1247         while (1) {
1248                 got = 0;
1249                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want,
1250                                     -1, &got, &pinned_page);
1251                 if (ret == 0)
1252                         break;
1253                 if (ret != -ERESTARTSYS) {
1254                         WARN_ON(1);
1255                         return VM_FAULT_SIGBUS;
1256                 }
1257         }
1258         dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1259              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got));
1260
1261         if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1262             ci->i_inline_version == CEPH_INLINE_NONE)
1263                 ret = filemap_fault(vma, vmf);
1264         else
1265                 ret = -EAGAIN;
1266
1267         dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
1268              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
1269         if (pinned_page)
1270                 page_cache_release(pinned_page);
1271         ceph_put_cap_refs(ci, got);
1272
1273         if (ret != -EAGAIN)
1274                 return ret;
1275
1276         /* read inline data */
1277         if (off >= PAGE_CACHE_SIZE) {
1278                 /* does not support inline data > PAGE_SIZE */
1279                 ret = VM_FAULT_SIGBUS;
1280         } else {
1281                 int ret1;
1282                 struct address_space *mapping = inode->i_mapping;
1283                 struct page *page = find_or_create_page(mapping, 0,
1284                                                 mapping_gfp_mask(mapping) &
1285                                                 ~__GFP_FS);
1286                 if (!page) {
1287                         ret = VM_FAULT_OOM;
1288                         goto out;
1289                 }
1290                 ret1 = __ceph_do_getattr(inode, page,
1291                                          CEPH_STAT_CAP_INLINE_DATA, true);
1292                 if (ret1 < 0 || off >= i_size_read(inode)) {
1293                         unlock_page(page);
1294                         page_cache_release(page);
1295                         ret = VM_FAULT_SIGBUS;
1296                         goto out;
1297                 }
1298                 if (ret1 < PAGE_CACHE_SIZE)
1299                         zero_user_segment(page, ret1, PAGE_CACHE_SIZE);
1300                 else
1301                         flush_dcache_page(page);
1302                 SetPageUptodate(page);
1303                 vmf->page = page;
1304                 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1305         }
1306 out:
1307         dout("filemap_fault %p %llu~%zd read inline data ret %d\n",
1308              inode, off, (size_t)PAGE_CACHE_SIZE, ret);
1309         return ret;
1310 }
1311
1312 /*
1313  * Reuse write_begin here for simplicity.
1314  */
1315 static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1316 {
1317         struct inode *inode = file_inode(vma->vm_file);
1318         struct ceph_inode_info *ci = ceph_inode(inode);
1319         struct ceph_file_info *fi = vma->vm_file->private_data;
1320         struct ceph_cap_flush *prealloc_cf;
1321         struct page *page = vmf->page;
1322         loff_t off = page_offset(page);
1323         loff_t size = i_size_read(inode);
1324         size_t len;
1325         int want, got, ret;
1326
1327         prealloc_cf = ceph_alloc_cap_flush();
1328         if (!prealloc_cf)
1329                 return VM_FAULT_SIGBUS;
1330
1331         if (ci->i_inline_version != CEPH_INLINE_NONE) {
1332                 struct page *locked_page = NULL;
1333                 if (off == 0) {
1334                         lock_page(page);
1335                         locked_page = page;
1336                 }
1337                 ret = ceph_uninline_data(vma->vm_file, locked_page);
1338                 if (locked_page)
1339                         unlock_page(locked_page);
1340                 if (ret < 0) {
1341                         ret = VM_FAULT_SIGBUS;
1342                         goto out_free;
1343                 }
1344         }
1345
1346         if (off + PAGE_CACHE_SIZE <= size)
1347                 len = PAGE_CACHE_SIZE;
1348         else
1349                 len = size & ~PAGE_CACHE_MASK;
1350
1351         dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1352              inode, ceph_vinop(inode), off, len, size);
1353         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1354                 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1355         else
1356                 want = CEPH_CAP_FILE_BUFFER;
1357         while (1) {
1358                 got = 0;
1359                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
1360                                     &got, NULL);
1361                 if (ret == 0)
1362                         break;
1363                 if (ret != -ERESTARTSYS) {
1364                         WARN_ON(1);
1365                         ret = VM_FAULT_SIGBUS;
1366                         goto out_free;
1367                 }
1368         }
1369         dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1370              inode, off, len, ceph_cap_string(got));
1371
1372         /* Update time before taking page lock */
1373         file_update_time(vma->vm_file);
1374
1375         lock_page(page);
1376
1377         ret = VM_FAULT_NOPAGE;
1378         if ((off > size) ||
1379             (page->mapping != inode->i_mapping))
1380                 goto out;
1381
1382         ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1383         if (ret == 0) {
1384                 /* success.  we'll keep the page locked. */
1385                 set_page_dirty(page);
1386                 ret = VM_FAULT_LOCKED;
1387         } else {
1388                 if (ret == -ENOMEM)
1389                         ret = VM_FAULT_OOM;
1390                 else
1391                         ret = VM_FAULT_SIGBUS;
1392         }
1393 out:
1394         if (ret != VM_FAULT_LOCKED)
1395                 unlock_page(page);
1396         if (ret == VM_FAULT_LOCKED ||
1397             ci->i_inline_version != CEPH_INLINE_NONE) {
1398                 int dirty;
1399                 spin_lock(&ci->i_ceph_lock);
1400                 ci->i_inline_version = CEPH_INLINE_NONE;
1401                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1402                                                &prealloc_cf);
1403                 spin_unlock(&ci->i_ceph_lock);
1404                 if (dirty)
1405                         __mark_inode_dirty(inode, dirty);
1406         }
1407
1408         dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
1409              inode, off, len, ceph_cap_string(got), ret);
1410         ceph_put_cap_refs(ci, got);
1411 out_free:
1412         ceph_free_cap_flush(prealloc_cf);
1413
1414         return ret;
1415 }
1416
1417 void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1418                            char *data, size_t len)
1419 {
1420         struct address_space *mapping = inode->i_mapping;
1421         struct page *page;
1422
1423         if (locked_page) {
1424                 page = locked_page;
1425         } else {
1426                 if (i_size_read(inode) == 0)
1427                         return;
1428                 page = find_or_create_page(mapping, 0,
1429                                            mapping_gfp_mask(mapping) & ~__GFP_FS);
1430                 if (!page)
1431                         return;
1432                 if (PageUptodate(page)) {
1433                         unlock_page(page);
1434                         page_cache_release(page);
1435                         return;
1436                 }
1437         }
1438
1439         dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1440              inode, ceph_vinop(inode), len, locked_page);
1441
1442         if (len > 0) {
1443                 void *kaddr = kmap_atomic(page);
1444                 memcpy(kaddr, data, len);
1445                 kunmap_atomic(kaddr);
1446         }
1447
1448         if (page != locked_page) {
1449                 if (len < PAGE_CACHE_SIZE)
1450                         zero_user_segment(page, len, PAGE_CACHE_SIZE);
1451                 else
1452                         flush_dcache_page(page);
1453
1454                 SetPageUptodate(page);
1455                 unlock_page(page);
1456                 page_cache_release(page);
1457         }
1458 }
1459
1460 int ceph_uninline_data(struct file *filp, struct page *locked_page)
1461 {
1462         struct inode *inode = file_inode(filp);
1463         struct ceph_inode_info *ci = ceph_inode(inode);
1464         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1465         struct ceph_osd_request *req;
1466         struct page *page = NULL;
1467         u64 len, inline_version;
1468         int err = 0;
1469         bool from_pagecache = false;
1470
1471         spin_lock(&ci->i_ceph_lock);
1472         inline_version = ci->i_inline_version;
1473         spin_unlock(&ci->i_ceph_lock);
1474
1475         dout("uninline_data %p %llx.%llx inline_version %llu\n",
1476              inode, ceph_vinop(inode), inline_version);
1477
1478         if (inline_version == 1 || /* initial version, no data */
1479             inline_version == CEPH_INLINE_NONE)
1480                 goto out;
1481
1482         if (locked_page) {
1483                 page = locked_page;
1484                 WARN_ON(!PageUptodate(page));
1485         } else if (ceph_caps_issued(ci) &
1486                    (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1487                 page = find_get_page(inode->i_mapping, 0);
1488                 if (page) {
1489                         if (PageUptodate(page)) {
1490                                 from_pagecache = true;
1491                                 lock_page(page);
1492                         } else {
1493                                 page_cache_release(page);
1494                                 page = NULL;
1495                         }
1496                 }
1497         }
1498
1499         if (page) {
1500                 len = i_size_read(inode);
1501                 if (len > PAGE_CACHE_SIZE)
1502                         len = PAGE_CACHE_SIZE;
1503         } else {
1504                 page = __page_cache_alloc(GFP_NOFS);
1505                 if (!page) {
1506                         err = -ENOMEM;
1507                         goto out;
1508                 }
1509                 err = __ceph_do_getattr(inode, page,
1510                                         CEPH_STAT_CAP_INLINE_DATA, true);
1511                 if (err < 0) {
1512                         /* no inline data */
1513                         if (err == -ENODATA)
1514                                 err = 0;
1515                         goto out;
1516                 }
1517                 len = err;
1518         }
1519
1520         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1521                                     ceph_vino(inode), 0, &len, 0, 1,
1522                                     CEPH_OSD_OP_CREATE,
1523                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1524                                     ceph_empty_snapc, 0, 0, false);
1525         if (IS_ERR(req)) {
1526                 err = PTR_ERR(req);
1527                 goto out;
1528         }
1529
1530         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1531         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1532         if (!err)
1533                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1534         ceph_osdc_put_request(req);
1535         if (err < 0)
1536                 goto out;
1537
1538         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1539                                     ceph_vino(inode), 0, &len, 1, 3,
1540                                     CEPH_OSD_OP_WRITE,
1541                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1542                                     ceph_empty_snapc,
1543                                     ci->i_truncate_seq, ci->i_truncate_size,
1544                                     false);
1545         if (IS_ERR(req)) {
1546                 err = PTR_ERR(req);
1547                 goto out;
1548         }
1549
1550         osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1551
1552         {
1553                 __le64 xattr_buf = cpu_to_le64(inline_version);
1554                 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1555                                             "inline_version", &xattr_buf,
1556                                             sizeof(xattr_buf),
1557                                             CEPH_OSD_CMPXATTR_OP_GT,
1558                                             CEPH_OSD_CMPXATTR_MODE_U64);
1559                 if (err)
1560                         goto out_put;
1561         }
1562
1563         {
1564                 char xattr_buf[32];
1565                 int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1566                                          "%llu", inline_version);
1567                 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1568                                             "inline_version",
1569                                             xattr_buf, xattr_len, 0, 0);
1570                 if (err)
1571                         goto out_put;
1572         }
1573
1574         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1575         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1576         if (!err)
1577                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1578 out_put:
1579         ceph_osdc_put_request(req);
1580         if (err == -ECANCELED)
1581                 err = 0;
1582 out:
1583         if (page && page != locked_page) {
1584                 if (from_pagecache) {
1585                         unlock_page(page);
1586                         page_cache_release(page);
1587                 } else
1588                         __free_pages(page, 0);
1589         }
1590
1591         dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1592              inode, ceph_vinop(inode), inline_version, err);
1593         return err;
1594 }
1595
1596 static struct vm_operations_struct ceph_vmops = {
1597         .fault          = ceph_filemap_fault,
1598         .page_mkwrite   = ceph_page_mkwrite,
1599 };
1600
1601 int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1602 {
1603         struct address_space *mapping = file->f_mapping;
1604
1605         if (!mapping->a_ops->readpage)
1606                 return -ENOEXEC;
1607         file_accessed(file);
1608         vma->vm_ops = &ceph_vmops;
1609         return 0;
1610 }
1611
1612 enum {
1613         POOL_READ       = 1,
1614         POOL_WRITE      = 2,
1615 };
1616
1617 static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
1618 {
1619         struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1620         struct ceph_mds_client *mdsc = fsc->mdsc;
1621         struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1622         struct rb_node **p, *parent;
1623         struct ceph_pool_perm *perm;
1624         struct page **pages;
1625         int err = 0, err2 = 0, have = 0;
1626
1627         down_read(&mdsc->pool_perm_rwsem);
1628         p = &mdsc->pool_perm_tree.rb_node;
1629         while (*p) {
1630                 perm = rb_entry(*p, struct ceph_pool_perm, node);
1631                 if (pool < perm->pool)
1632                         p = &(*p)->rb_left;
1633                 else if (pool > perm->pool)
1634                         p = &(*p)->rb_right;
1635                 else {
1636                         have = perm->perm;
1637                         break;
1638                 }
1639         }
1640         up_read(&mdsc->pool_perm_rwsem);
1641         if (*p)
1642                 goto out;
1643
1644         dout("__ceph_pool_perm_get pool %u no perm cached\n", pool);
1645
1646         down_write(&mdsc->pool_perm_rwsem);
1647         parent = NULL;
1648         while (*p) {
1649                 parent = *p;
1650                 perm = rb_entry(parent, struct ceph_pool_perm, node);
1651                 if (pool < perm->pool)
1652                         p = &(*p)->rb_left;
1653                 else if (pool > perm->pool)
1654                         p = &(*p)->rb_right;
1655                 else {
1656                         have = perm->perm;
1657                         break;
1658                 }
1659         }
1660         if (*p) {
1661                 up_write(&mdsc->pool_perm_rwsem);
1662                 goto out;
1663         }
1664
1665         rd_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1666                                          ceph_empty_snapc,
1667                                          1, false, GFP_NOFS);
1668         if (!rd_req) {
1669                 err = -ENOMEM;
1670                 goto out_unlock;
1671         }
1672
1673         rd_req->r_flags = CEPH_OSD_FLAG_READ;
1674         osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1675         rd_req->r_base_oloc.pool = pool;
1676         snprintf(rd_req->r_base_oid.name, sizeof(rd_req->r_base_oid.name),
1677                  "%llx.00000000", ci->i_vino.ino);
1678         rd_req->r_base_oid.name_len = strlen(rd_req->r_base_oid.name);
1679
1680         wr_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1681                                          ceph_empty_snapc,
1682                                          1, false, GFP_NOFS);
1683         if (!wr_req) {
1684                 err = -ENOMEM;
1685                 goto out_unlock;
1686         }
1687
1688         wr_req->r_flags = CEPH_OSD_FLAG_WRITE |
1689                           CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK;
1690         osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
1691         wr_req->r_base_oloc.pool = pool;
1692         wr_req->r_base_oid = rd_req->r_base_oid;
1693
1694         /* one page should be large enough for STAT data */
1695         pages = ceph_alloc_page_vector(1, GFP_KERNEL);
1696         if (IS_ERR(pages)) {
1697                 err = PTR_ERR(pages);
1698                 goto out_unlock;
1699         }
1700
1701         osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
1702                                      0, false, true);
1703         ceph_osdc_build_request(rd_req, 0, NULL, CEPH_NOSNAP,
1704                                 &ci->vfs_inode.i_mtime);
1705         err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
1706
1707         ceph_osdc_build_request(wr_req, 0, NULL, CEPH_NOSNAP,
1708                                 &ci->vfs_inode.i_mtime);
1709         err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
1710
1711         if (!err)
1712                 err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
1713         if (!err2)
1714                 err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
1715
1716         if (err >= 0 || err == -ENOENT)
1717                 have |= POOL_READ;
1718         else if (err != -EPERM)
1719                 goto out_unlock;
1720
1721         if (err2 == 0 || err2 == -EEXIST)
1722                 have |= POOL_WRITE;
1723         else if (err2 != -EPERM) {
1724                 err = err2;
1725                 goto out_unlock;
1726         }
1727
1728         perm = kmalloc(sizeof(*perm), GFP_NOFS);
1729         if (!perm) {
1730                 err = -ENOMEM;
1731                 goto out_unlock;
1732         }
1733
1734         perm->pool = pool;
1735         perm->perm = have;
1736         rb_link_node(&perm->node, parent, p);
1737         rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
1738         err = 0;
1739 out_unlock:
1740         up_write(&mdsc->pool_perm_rwsem);
1741
1742         if (rd_req)
1743                 ceph_osdc_put_request(rd_req);
1744         if (wr_req)
1745                 ceph_osdc_put_request(wr_req);
1746 out:
1747         if (!err)
1748                 err = have;
1749         dout("__ceph_pool_perm_get pool %u result = %d\n", pool, err);
1750         return err;
1751 }
1752
1753 int ceph_pool_perm_check(struct ceph_inode_info *ci, int need)
1754 {
1755         u32 pool;
1756         int ret, flags;
1757
1758         if (ceph_test_mount_opt(ceph_inode_to_client(&ci->vfs_inode),
1759                                 NOPOOLPERM))
1760                 return 0;
1761
1762         spin_lock(&ci->i_ceph_lock);
1763         flags = ci->i_ceph_flags;
1764         pool = ceph_file_layout_pg_pool(ci->i_layout);
1765         spin_unlock(&ci->i_ceph_lock);
1766 check:
1767         if (flags & CEPH_I_POOL_PERM) {
1768                 if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
1769                         dout("ceph_pool_perm_check pool %u no read perm\n",
1770                              pool);
1771                         return -EPERM;
1772                 }
1773                 if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
1774                         dout("ceph_pool_perm_check pool %u no write perm\n",
1775                              pool);
1776                         return -EPERM;
1777                 }
1778                 return 0;
1779         }
1780
1781         ret = __ceph_pool_perm_get(ci, pool);
1782         if (ret < 0)
1783                 return ret;
1784
1785         flags = CEPH_I_POOL_PERM;
1786         if (ret & POOL_READ)
1787                 flags |= CEPH_I_POOL_RD;
1788         if (ret & POOL_WRITE)
1789                 flags |= CEPH_I_POOL_WR;
1790
1791         spin_lock(&ci->i_ceph_lock);
1792         if (pool == ceph_file_layout_pg_pool(ci->i_layout)) {
1793                 ci->i_ceph_flags = flags;
1794         } else {
1795                 pool = ceph_file_layout_pg_pool(ci->i_layout);
1796                 flags = ci->i_ceph_flags;
1797         }
1798         spin_unlock(&ci->i_ceph_lock);
1799         goto check;
1800 }
1801
1802 void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
1803 {
1804         struct ceph_pool_perm *perm;
1805         struct rb_node *n;
1806
1807         while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
1808                 n = rb_first(&mdsc->pool_perm_tree);
1809                 perm = rb_entry(n, struct ceph_pool_perm, node);
1810                 rb_erase(n, &mdsc->pool_perm_tree);
1811                 kfree(perm);
1812         }
1813 }