fs/ceph/addr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/backing-dev.h>
   5 #include <linux/fs.h>
   6 #include <linux/mm.h>
   7 #include <linux/swap.h>
   8 #include <linux/pagemap.h>
   9 #include <linux/slab.h>
  10 #include <linux/pagevec.h>
  11 #include <linux/task_io_accounting_ops.h>
  12 #include <linux/signal.h>
  13 #include <linux/iversion.h>
  14 #include <linux/ktime.h>
  15 #include <linux/netfs.h>
  16
  17 #include "super.h"
  18 #include "mds_client.h"
  19 #include "cache.h"
  20 #include "metric.h"
  21 #include <linux/ceph/osd_client.h>
  22 #include <linux/ceph/striper.h>
  23
  24 /*
  25  * Ceph address space ops.
  26  *
  27  * There are a few funny things going on here.
  28  *
  29  * The page->private field is used to reference a struct
  30  * ceph_snap_context for _every_ dirty page.  This indicates which
  31  * snapshot the page was logically dirtied in, and thus which snap
  32  * context needs to be associated with the osd write during writeback.
  33  *
  34  * Similarly, struct ceph_inode_info maintains a set of counters to
  35  * count dirty pages on the inode.  In the absence of snapshots,
  36  * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
  37  *
  38  * When a snapshot is taken (that is, when the client receives
  39  * notification that a snapshot was taken), each inode with caps and
  40  * with dirty pages (dirty pages implies there is a cap) gets a new
  41  * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
  42  * order, new snaps go to the tail).  The i_wrbuffer_ref_head count is
  43  * moved to capsnap->dirty. (Unless a sync write is currently in
  44  * progress.  In that case, the capsnap is said to be "pending", new
  45  * writes cannot start, and the capsnap isn't "finalized" until the
  46  * write completes (or fails) and a final size/mtime for the inode for
  47  * that snap can be settled upon.)  i_wrbuffer_ref_head is reset to 0.
  48  *
  49  * On writeback, we must submit writes to the osd IN SNAP ORDER.  So,
  50  * we look for the first capsnap in i_cap_snaps and write out pages in
  51  * that snap context _only_.  Then we move on to the next capsnap,
  52  * eventually reaching the "live" or "head" context (i.e., pages that
  53  * are not yet snapped) and are writing the most recently dirtied
  54  * pages.
  55  *
  56  * Invalidate and so forth must take care to ensure the dirty page
  57  * accounting is preserved.
  58  */
  59
  60 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
  61 #define CONGESTION_OFF_THRESH(congestion_kb)                            \
  62         (CONGESTION_ON_THRESH(congestion_kb) -                          \
  63          (CONGESTION_ON_THRESH(congestion_kb) >> 2))
  64
  65 static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len,
  66                                         struct folio **foliop, void **_fsdata);
  67
  68 static inline struct ceph_snap_context *page_snap_context(struct page *page)
  69 {
  70         if (PagePrivate(page))
  71                 return (void *)page->private;
  72         return NULL;
  73 }
  74
  75 /*
  76  * Dirty a page.  Optimistically adjust accounting, on the assumption
  77  * that we won't race with invalidate.  If we do, readjust.
  78  */
  79 static bool ceph_dirty_folio(struct address_space *mapping, struct folio *folio)
  80 {
  81         struct inode *inode;
  82         struct ceph_inode_info *ci;
  83         struct ceph_snap_context *snapc;
  84
  85         if (folio_test_dirty(folio)) {
  86                 dout("%p dirty_folio %p idx %lu -- already dirty\n",
  87                      mapping->host, folio, folio->index);
  88                 VM_BUG_ON_FOLIO(!folio_test_private(folio), folio);
  89                 return false;
  90         }
  91
  92         inode = mapping->host;
  93         ci = ceph_inode(inode);
  94
  95         /* dirty the head */
  96         spin_lock(&ci->i_ceph_lock);
  97         BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
  98         if (__ceph_have_pending_cap_snap(ci)) {
  99                 struct ceph_cap_snap *capsnap =
 100                                 list_last_entry(&ci->i_cap_snaps,
 101                                                 struct ceph_cap_snap,
 102                                                 ci_item);
 103                 snapc = ceph_get_snap_context(capsnap->context);
 104                 capsnap->dirty_pages++;
 105         } else {
 106                 BUG_ON(!ci->i_head_snapc);
 107                 snapc = ceph_get_snap_context(ci->i_head_snapc);
 108                 ++ci->i_wrbuffer_ref_head;
 109         }
 110         if (ci->i_wrbuffer_ref == 0)
 111                 ihold(inode);
 112         ++ci->i_wrbuffer_ref;
 113         dout("%p dirty_folio %p idx %lu head %d/%d -> %d/%d "
 114              "snapc %p seq %lld (%d snaps)\n",
 115              mapping->host, folio, folio->index,
 116              ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
 117              ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
 118              snapc, snapc->seq, snapc->num_snaps);
 119         spin_unlock(&ci->i_ceph_lock);
 120
 121         /*
 122          * Reference snap context in folio->private.  Also set
 123          * PagePrivate so that we get invalidate_folio callback.
 124          */
 125         VM_WARN_ON_FOLIO(folio->private, folio);
 126         folio_attach_private(folio, snapc);
 127
 128         return ceph_fscache_dirty_folio(mapping, folio);
 129 }
 130
 131 /*
 132  * If we are truncating the full folio (i.e. offset == 0), adjust the
 133  * dirty folio counters appropriately.  Only called if there is private
 134  * data on the folio.
 135  */
 136 static void ceph_invalidate_folio(struct folio *folio, size_t offset,
 137                                 size_t length)
 138 {
 139         struct inode *inode;
 140         struct ceph_inode_info *ci;
 141         struct ceph_snap_context *snapc;
 142
 143         inode = folio->mapping->host;
 144         ci = ceph_inode(inode);
 145
 146         if (offset != 0 || length != folio_size(folio)) {
 147                 dout("%p invalidate_folio idx %lu partial dirty page %zu~%zu\n",
 148                      inode, folio->index, offset, length);
 149                 return;
 150         }
 151
 152         WARN_ON(!folio_test_locked(folio));
 153         if (folio_test_private(folio)) {
 154                 dout("%p invalidate_folio idx %lu full dirty page\n",
 155                      inode, folio->index);
 156
 157                 snapc = folio_detach_private(folio);
 158                 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 159                 ceph_put_snap_context(snapc);
 160         }
 161
 162         folio_wait_fscache(folio);
 163 }
 164
 165 static bool ceph_release_folio(struct folio *folio, gfp_t gfp)
 166 {
 167         struct inode *inode = folio->mapping->host;
 168
 169         dout("%llx:%llx release_folio idx %lu (%sdirty)\n",
 170              ceph_vinop(inode),
 171              folio->index, folio_test_dirty(folio) ? "" : "not ");
 172
 173         if (folio_test_private(folio))
 174                 return false;
 175
 176         if (folio_test_fscache(folio)) {
 177                 if (current_is_kswapd() || !(gfp & __GFP_FS))
 178                         return false;
 179                 folio_wait_fscache(folio);
 180         }
 181         ceph_fscache_note_page_release(inode);
 182         return true;
 183 }
 184
 185 static void ceph_netfs_expand_readahead(struct netfs_io_request *rreq)
 186 {
 187         struct inode *inode = rreq->inode;
 188         struct ceph_inode_info *ci = ceph_inode(inode);
 189         struct ceph_file_layout *lo = &ci->i_layout;
 190         u32 blockoff;
 191         u64 blockno;
 192
 193         /* Expand the start downward */
 194         blockno = div_u64_rem(rreq->start, lo->stripe_unit, &blockoff);
 195         rreq->start = blockno * lo->stripe_unit;
 196         rreq->len += blockoff;
 197
 198         /* Now, round up the length to the next block */
 199         rreq->len = roundup(rreq->len, lo->stripe_unit);
 200 }
 201
 202 static bool ceph_netfs_clamp_length(struct netfs_io_subrequest *subreq)
 203 {
 204         struct inode *inode = subreq->rreq->inode;
 205         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 206         struct ceph_inode_info *ci = ceph_inode(inode);
 207         u64 objno, objoff;
 208         u32 xlen;
 209
 210         /* Truncate the extent at the end of the current block */
 211         ceph_calc_file_object_mapping(&ci->i_layout, subreq->start, subreq->len,
 212                                       &objno, &objoff, &xlen);
 213         subreq->len = min(xlen, fsc->mount_options->rsize);
 214         return true;
 215 }
 216
 217 static void finish_netfs_read(struct ceph_osd_request *req)
 218 {
 219         struct ceph_fs_client *fsc = ceph_inode_to_client(req->r_inode);
 220         struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
 221         struct netfs_io_subrequest *subreq = req->r_priv;
 222         int num_pages;
 223         int err = req->r_result;
 224
 225         ceph_update_read_metrics(&fsc->mdsc->metric, req->r_start_latency,
 226                                  req->r_end_latency, osd_data->length, err);
 227
 228         dout("%s: result %d subreq->len=%zu i_size=%lld\n", __func__, req->r_result,
 229              subreq->len, i_size_read(req->r_inode));
 230
 231         /* no object means success but no data */
 232         if (err == -ENOENT)
 233                 err = 0;
 234         else if (err == -EBLOCKLISTED)
 235                 fsc->blocklisted = true;
 236
 237         if (err >= 0 && err < subreq->len)
 238                 __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
 239
 240         netfs_subreq_terminated(subreq, err, false);
 241
 242         num_pages = calc_pages_for(osd_data->alignment, osd_data->length);
 243         ceph_put_page_vector(osd_data->pages, num_pages, false);
 244         iput(req->r_inode);
 245 }
 246
 247 static bool ceph_netfs_issue_op_inline(struct netfs_io_subrequest *subreq)
 248 {
 249         struct netfs_io_request *rreq = subreq->rreq;
 250         struct inode *inode = rreq->inode;
 251         struct ceph_mds_reply_info_parsed *rinfo;
 252         struct ceph_mds_reply_info_in *iinfo;
 253         struct ceph_mds_request *req;
 254         struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
 255         struct ceph_inode_info *ci = ceph_inode(inode);
 256         struct iov_iter iter;
 257         ssize_t err = 0;
 258         size_t len;
 259         int mode;
 260
 261         __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
 262         __clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);
 263
 264         if (subreq->start >= inode->i_size)
 265                 goto out;
 266
 267         /* We need to fetch the inline data. */
 268         mode = ceph_try_to_choose_auth_mds(inode, CEPH_STAT_CAP_INLINE_DATA);
 269         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, mode);
 270         if (IS_ERR(req)) {
 271                 err = PTR_ERR(req);
 272                 goto out;
 273         }
 274         req->r_ino1 = ci->i_vino;
 275         req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INLINE_DATA);
 276         req->r_num_caps = 2;
 277
 278         err = ceph_mdsc_do_request(mdsc, NULL, req);
 279         if (err < 0)
 280                 goto out;
 281
 282         rinfo = &req->r_reply_info;
 283         iinfo = &rinfo->targeti;
 284         if (iinfo->inline_version == CEPH_INLINE_NONE) {
 285                 /* The data got uninlined */
 286                 ceph_mdsc_put_request(req);
 287                 return false;
 288         }
 289
 290         len = min_t(size_t, iinfo->inline_len - subreq->start, subreq->len);
 291         iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages, subreq->start, len);
 292         err = copy_to_iter(iinfo->inline_data + subreq->start, len, &iter);
 293         if (err == 0)
 294                 err = -EFAULT;
 295
 296         ceph_mdsc_put_request(req);
 297 out:
 298         netfs_subreq_terminated(subreq, err, false);
 299         return true;
 300 }
 301
 302 static void ceph_netfs_issue_read(struct netfs_io_subrequest *subreq)
 303 {
 304         struct netfs_io_request *rreq = subreq->rreq;
 305         struct inode *inode = rreq->inode;
 306         struct ceph_inode_info *ci = ceph_inode(inode);
 307         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 308         struct ceph_osd_request *req;
 309         struct ceph_vino vino = ceph_vino(inode);
 310         struct iov_iter iter;
 311         struct page **pages;
 312         size_t page_off;
 313         int err = 0;
 314         u64 len = subreq->len;
 315
 316         if (ceph_has_inline_data(ci) && ceph_netfs_issue_op_inline(subreq))
 317                 return;
 318
 319         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout, vino, subreq->start, &len,
 320                         0, 1, CEPH_OSD_OP_READ,
 321                         CEPH_OSD_FLAG_READ | fsc->client->osdc.client->options->read_from_replica,
 322                         NULL, ci->i_truncate_seq, ci->i_truncate_size, false);
 323         if (IS_ERR(req)) {
 324                 err = PTR_ERR(req);
 325                 req = NULL;
 326                 goto out;
 327         }
 328
 329         dout("%s: pos=%llu orig_len=%zu len=%llu\n", __func__, subreq->start, subreq->len, len);
 330         iov_iter_xarray(&iter, ITER_DEST, &rreq->mapping->i_pages, subreq->start, len);
 331         err = iov_iter_get_pages_alloc2(&iter, &pages, len, &page_off);
 332         if (err < 0) {
 333                 dout("%s: iov_ter_get_pages_alloc returned %d\n", __func__, err);
 334                 goto out;
 335         }
 336
 337         /* should always give us a page-aligned read */
 338         WARN_ON_ONCE(page_off);
 339         len = err;
 340         err = 0;
 341
 342         osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
 343         req->r_callback = finish_netfs_read;
 344         req->r_priv = subreq;
 345         req->r_inode = inode;
 346         ihold(inode);
 347
 348         ceph_osdc_start_request(req->r_osdc, req);
 349 out:
 350         ceph_osdc_put_request(req);
 351         if (err)
 352                 netfs_subreq_terminated(subreq, err, false);
 353         dout("%s: result %d\n", __func__, err);
 354 }
 355
 356 static int ceph_init_request(struct netfs_io_request *rreq, struct file *file)
 357 {
 358         struct inode *inode = rreq->inode;
 359         int got = 0, want = CEPH_CAP_FILE_CACHE;
 360         int ret = 0;
 361
 362         if (rreq->origin != NETFS_READAHEAD)
 363                 return 0;
 364
 365         if (file) {
 366                 struct ceph_rw_context *rw_ctx;
 367                 struct ceph_file_info *fi = file->private_data;
 368
 369                 rw_ctx = ceph_find_rw_context(fi);
 370                 if (rw_ctx)
 371                         return 0;
 372         }
 373
 374         /*
 375          * readahead callers do not necessarily hold Fcb caps
 376          * (e.g. fadvise, madvise).
 377          */
 378         ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want, true, &got);
 379         if (ret < 0) {
 380                 dout("start_read %p, error getting cap\n", inode);
 381                 return ret;
 382         }
 383
 384         if (!(got & want)) {
 385                 dout("start_read %p, no cache cap\n", inode);
 386                 return -EACCES;
 387         }
 388         if (ret == 0)
 389                 return -EACCES;
 390
 391         rreq->netfs_priv = (void *)(uintptr_t)got;
 392         return 0;
 393 }
 394
 395 static void ceph_netfs_free_request(struct netfs_io_request *rreq)
 396 {
 397         struct ceph_inode_info *ci = ceph_inode(rreq->inode);
 398         int got = (uintptr_t)rreq->netfs_priv;
 399
 400         if (got)
 401                 ceph_put_cap_refs(ci, got);
 402 }
 403
 404 const struct netfs_request_ops ceph_netfs_ops = {
 405         .init_request           = ceph_init_request,
 406         .free_request           = ceph_netfs_free_request,
 407         .begin_cache_operation  = ceph_begin_cache_operation,
 408         .issue_read             = ceph_netfs_issue_read,
 409         .expand_readahead       = ceph_netfs_expand_readahead,
 410         .clamp_length           = ceph_netfs_clamp_length,
 411         .check_write_begin      = ceph_netfs_check_write_begin,
 412 };
 413
 414 #ifdef CONFIG_CEPH_FSCACHE
 415 static void ceph_set_page_fscache(struct page *page)
 416 {
 417         set_page_fscache(page);
 418 }
 419
 420 static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
 421 {
 422         struct inode *inode = priv;
 423
 424         if (IS_ERR_VALUE(error) && error != -ENOBUFS)
 425                 ceph_fscache_invalidate(inode, false);
 426 }
 427
 428 static void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
 429 {
 430         struct ceph_inode_info *ci = ceph_inode(inode);
 431         struct fscache_cookie *cookie = ceph_fscache_cookie(ci);
 432
 433         fscache_write_to_cache(cookie, inode->i_mapping, off, len, i_size_read(inode),
 434                                ceph_fscache_write_terminated, inode, caching);
 435 }
 436 #else
 437 static inline void ceph_set_page_fscache(struct page *page)
 438 {
 439 }
 440
 441 static inline void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
 442 {
 443 }
 444 #endif /* CONFIG_CEPH_FSCACHE */
 445
 446 struct ceph_writeback_ctl
 447 {
 448         loff_t i_size;
 449         u64 truncate_size;
 450         u32 truncate_seq;
 451         bool size_stable;
 452         bool head_snapc;
 453 };
 454
 455 /*
 456  * Get ref for the oldest snapc for an inode with dirty data... that is, the
 457  * only snap context we are allowed to write back.
 458  */
 459 static struct ceph_snap_context *
 460 get_oldest_context(struct inode *inode, struct ceph_writeback_ctl *ctl,
 461                    struct ceph_snap_context *page_snapc)
 462 {
 463         struct ceph_inode_info *ci = ceph_inode(inode);
 464         struct ceph_snap_context *snapc = NULL;
 465         struct ceph_cap_snap *capsnap = NULL;
 466
 467         spin_lock(&ci->i_ceph_lock);
 468         list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 469                 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
 470                      capsnap->context, capsnap->dirty_pages);
 471                 if (!capsnap->dirty_pages)
 472                         continue;
 473
 474                 /* get i_size, truncate_{seq,size} for page_snapc? */
 475                 if (snapc && capsnap->context != page_snapc)
 476                         continue;
 477
 478                 if (ctl) {
 479                         if (capsnap->writing) {
 480                                 ctl->i_size = i_size_read(inode);
 481                                 ctl->size_stable = false;
 482                         } else {
 483                                 ctl->i_size = capsnap->size;
 484                                 ctl->size_stable = true;
 485                         }
 486                         ctl->truncate_size = capsnap->truncate_size;
 487                         ctl->truncate_seq = capsnap->truncate_seq;
 488                         ctl->head_snapc = false;
 489                 }
 490
 491                 if (snapc)
 492                         break;
 493
 494                 snapc = ceph_get_snap_context(capsnap->context);
 495                 if (!page_snapc ||
 496                     page_snapc == snapc ||
 497                     page_snapc->seq > snapc->seq)
 498                         break;
 499         }
 500         if (!snapc && ci->i_wrbuffer_ref_head) {
 501                 snapc = ceph_get_snap_context(ci->i_head_snapc);
 502                 dout(" head snapc %p has %d dirty pages\n",
 503                      snapc, ci->i_wrbuffer_ref_head);
 504                 if (ctl) {
 505                         ctl->i_size = i_size_read(inode);
 506                         ctl->truncate_size = ci->i_truncate_size;
 507                         ctl->truncate_seq = ci->i_truncate_seq;
 508                         ctl->size_stable = false;
 509                         ctl->head_snapc = true;
 510                 }
 511         }
 512         spin_unlock(&ci->i_ceph_lock);
 513         return snapc;
 514 }
 515
 516 static u64 get_writepages_data_length(struct inode *inode,
 517                                       struct page *page, u64 start)
 518 {
 519         struct ceph_inode_info *ci = ceph_inode(inode);
 520         struct ceph_snap_context *snapc = page_snap_context(page);
 521         struct ceph_cap_snap *capsnap = NULL;
 522         u64 end = i_size_read(inode);
 523
 524         if (snapc != ci->i_head_snapc) {
 525                 bool found = false;
 526                 spin_lock(&ci->i_ceph_lock);
 527                 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 528                         if (capsnap->context == snapc) {
 529                                 if (!capsnap->writing)
 530                                         end = capsnap->size;
 531                                 found = true;
 532                                 break;
 533                         }
 534                 }
 535                 spin_unlock(&ci->i_ceph_lock);
 536                 WARN_ON(!found);
 537         }
 538         if (end > page_offset(page) + thp_size(page))
 539                 end = page_offset(page) + thp_size(page);
 540         return end > start ? end - start : 0;
 541 }
 542
 543 /*
 544  * Write a single page, but leave the page locked.
 545  *
 546  * If we get a write error, mark the mapping for error, but still adjust the
 547  * dirty page accounting (i.e., page is no longer dirty).
 548  */
 549 static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 550 {
 551         struct folio *folio = page_folio(page);
 552         struct inode *inode = page->mapping->host;
 553         struct ceph_inode_info *ci = ceph_inode(inode);
 554         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 555         struct ceph_snap_context *snapc, *oldest;
 556         loff_t page_off = page_offset(page);
 557         int err;
 558         loff_t len = thp_size(page);
 559         struct ceph_writeback_ctl ceph_wbc;
 560         struct ceph_osd_client *osdc = &fsc->client->osdc;
 561         struct ceph_osd_request *req;
 562         bool caching = ceph_is_cache_enabled(inode);
 563
 564         dout("writepage %p idx %lu\n", page, page->index);
 565
 566         /* verify this is a writeable snap context */
 567         snapc = page_snap_context(page);
 568         if (!snapc) {
 569                 dout("writepage %p page %p not dirty?\n", inode, page);
 570                 return 0;
 571         }
 572         oldest = get_oldest_context(inode, &ceph_wbc, snapc);
 573         if (snapc->seq > oldest->seq) {
 574                 dout("writepage %p page %p snapc %p not writeable - noop\n",
 575                      inode, page, snapc);
 576                 /* we should only noop if called by kswapd */
 577                 WARN_ON(!(current->flags & PF_MEMALLOC));
 578                 ceph_put_snap_context(oldest);
 579                 redirty_page_for_writepage(wbc, page);
 580                 return 0;
 581         }
 582         ceph_put_snap_context(oldest);
 583
 584         /* is this a partial page at end of file? */
 585         if (page_off >= ceph_wbc.i_size) {
 586                 dout("folio at %lu beyond eof %llu\n", folio->index,
 587                                 ceph_wbc.i_size);
 588                 folio_invalidate(folio, 0, folio_size(folio));
 589                 return 0;
 590         }
 591
 592         if (ceph_wbc.i_size < page_off + len)
 593                 len = ceph_wbc.i_size - page_off;
 594
 595         dout("writepage %p page %p index %lu on %llu~%llu snapc %p seq %lld\n",
 596              inode, page, page->index, page_off, len, snapc, snapc->seq);
 597
 598         if (atomic_long_inc_return(&fsc->writeback_count) >
 599             CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
 600                 fsc->write_congested = true;
 601
 602         req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode), page_off, &len, 0, 1,
 603                                     CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE, snapc,
 604                                     ceph_wbc.truncate_seq, ceph_wbc.truncate_size,
 605                                     true);
 606         if (IS_ERR(req)) {
 607                 redirty_page_for_writepage(wbc, page);
 608                 return PTR_ERR(req);
 609         }
 610
 611         set_page_writeback(page);
 612         if (caching)
 613                 ceph_set_page_fscache(page);
 614         ceph_fscache_write_to_cache(inode, page_off, len, caching);
 615
 616         /* it may be a short write due to an object boundary */
 617         WARN_ON_ONCE(len > thp_size(page));
 618         osd_req_op_extent_osd_data_pages(req, 0, &page, len, 0, false, false);
 619         dout("writepage %llu~%llu (%llu bytes)\n", page_off, len, len);
 620
 621         req->r_mtime = inode->i_mtime;
 622         ceph_osdc_start_request(osdc, req);
 623         err = ceph_osdc_wait_request(osdc, req);
 624
 625         ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
 626                                   req->r_end_latency, len, err);
 627
 628         ceph_osdc_put_request(req);
 629         if (err == 0)
 630                 err = len;
 631
 632         if (err < 0) {
 633                 struct writeback_control tmp_wbc;
 634                 if (!wbc)
 635                         wbc = &tmp_wbc;
 636                 if (err == -ERESTARTSYS) {
 637                         /* killed by SIGKILL */
 638                         dout("writepage interrupted page %p\n", page);
 639                         redirty_page_for_writepage(wbc, page);
 640                         end_page_writeback(page);
 641                         return err;
 642                 }
 643                 if (err == -EBLOCKLISTED)
 644                         fsc->blocklisted = true;
 645                 dout("writepage setting page/mapping error %d %p\n",
 646                      err, page);
 647                 mapping_set_error(&inode->i_data, err);
 648                 wbc->pages_skipped++;
 649         } else {
 650                 dout("writepage cleaned page %p\n", page);
 651                 err = 0;  /* vfs expects us to return 0 */
 652         }
 653         oldest = detach_page_private(page);
 654         WARN_ON_ONCE(oldest != snapc);
 655         end_page_writeback(page);
 656         ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 657         ceph_put_snap_context(snapc);  /* page's reference */
 658
 659         if (atomic_long_dec_return(&fsc->writeback_count) <
 660             CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
 661                 fsc->write_congested = false;
 662
 663         return err;
 664 }
 665
 666 static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 667 {
 668         int err;
 669         struct inode *inode = page->mapping->host;
 670         BUG_ON(!inode);
 671         ihold(inode);
 672
 673         if (wbc->sync_mode == WB_SYNC_NONE &&
 674             ceph_inode_to_client(inode)->write_congested)
 675                 return AOP_WRITEPAGE_ACTIVATE;
 676
 677         wait_on_page_fscache(page);
 678
 679         err = writepage_nounlock(page, wbc);
 680         if (err == -ERESTARTSYS) {
 681                 /* direct memory reclaimer was killed by SIGKILL. return 0
 682                  * to prevent caller from setting mapping/page error */
 683                 err = 0;
 684         }
 685         unlock_page(page);
 686         iput(inode);
 687         return err;
 688 }
 689
 690 /*
 691  * async writeback completion handler.
 692  *
 693  * If we get an error, set the mapping error bit, but not the individual
 694  * page error bits.
 695  */
 696 static void writepages_finish(struct ceph_osd_request *req)
 697 {
 698         struct inode *inode = req->r_inode;
 699         struct ceph_inode_info *ci = ceph_inode(inode);
 700         struct ceph_osd_data *osd_data;
 701         struct page *page;
 702         int num_pages, total_pages = 0;
 703         int i, j;
 704         int rc = req->r_result;
 705         struct ceph_snap_context *snapc = req->r_snapc;
 706         struct address_space *mapping = inode->i_mapping;
 707         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 708         unsigned int len = 0;
 709         bool remove_page;
 710
 711         dout("writepages_finish %p rc %d\n", inode, rc);
 712         if (rc < 0) {
 713                 mapping_set_error(mapping, rc);
 714                 ceph_set_error_write(ci);
 715                 if (rc == -EBLOCKLISTED)
 716                         fsc->blocklisted = true;
 717         } else {
 718                 ceph_clear_error_write(ci);
 719         }
 720
 721         /*
 722          * We lost the cache cap, need to truncate the page before
 723          * it is unlocked, otherwise we'd truncate it later in the
 724          * page truncation thread, possibly losing some data that
 725          * raced its way in
 726          */
 727         remove_page = !(ceph_caps_issued(ci) &
 728                         (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO));
 729
 730         /* clean all pages */
 731         for (i = 0; i < req->r_num_ops; i++) {
 732                 if (req->r_ops[i].op != CEPH_OSD_OP_WRITE) {
 733                         pr_warn("%s incorrect op %d req %p index %d tid %llu\n",
 734                                 __func__, req->r_ops[i].op, req, i, req->r_tid);
 735                         break;
 736                 }
 737
 738                 osd_data = osd_req_op_extent_osd_data(req, i);
 739                 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 740                 len += osd_data->length;
 741                 num_pages = calc_pages_for((u64)osd_data->alignment,
 742                                            (u64)osd_data->length);
 743                 total_pages += num_pages;
 744                 for (j = 0; j < num_pages; j++) {
 745                         page = osd_data->pages[j];
 746                         BUG_ON(!page);
 747                         WARN_ON(!PageUptodate(page));
 748
 749                         if (atomic_long_dec_return(&fsc->writeback_count) <
 750                              CONGESTION_OFF_THRESH(
 751                                         fsc->mount_options->congestion_kb))
 752                                 fsc->write_congested = false;
 753
 754                         ceph_put_snap_context(detach_page_private(page));
 755                         end_page_writeback(page);
 756                         dout("unlocking %p\n", page);
 757
 758                         if (remove_page)
 759                                 generic_error_remove_page(inode->i_mapping,
 760                                                           page);
 761
 762                         unlock_page(page);
 763                 }
 764                 dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
 765                      inode, osd_data->length, rc >= 0 ? num_pages : 0);
 766
 767                 release_pages(osd_data->pages, num_pages);
 768         }
 769
 770         ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
 771                                   req->r_end_latency, len, rc);
 772
 773         ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
 774
 775         osd_data = osd_req_op_extent_osd_data(req, 0);
 776         if (osd_data->pages_from_pool)
 777                 mempool_free(osd_data->pages, ceph_wb_pagevec_pool);
 778         else
 779                 kfree(osd_data->pages);
 780         ceph_osdc_put_request(req);
 781 }
 782
 783 /*
 784  * initiate async writeback
 785  */
 786 static int ceph_writepages_start(struct address_space *mapping,
 787                                  struct writeback_control *wbc)
 788 {
 789         struct inode *inode = mapping->host;
 790         struct ceph_inode_info *ci = ceph_inode(inode);
 791         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 792         struct ceph_vino vino = ceph_vino(inode);
 793         pgoff_t index, start_index, end = -1;
 794         struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
 795         struct pagevec pvec;
 796         int rc = 0;
 797         unsigned int wsize = i_blocksize(inode);
 798         struct ceph_osd_request *req = NULL;
 799         struct ceph_writeback_ctl ceph_wbc;
 800         bool should_loop, range_whole = false;
 801         bool done = false;
 802         bool caching = ceph_is_cache_enabled(inode);
 803
 804         if (wbc->sync_mode == WB_SYNC_NONE &&
 805             fsc->write_congested)
 806                 return 0;
 807
 808         dout("writepages_start %p (mode=%s)\n", inode,
 809              wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
 810              (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
 811
 812         if (ceph_inode_is_shutdown(inode)) {
 813                 if (ci->i_wrbuffer_ref > 0) {
 814                         pr_warn_ratelimited(
 815                                 "writepage_start %p %lld forced umount\n",
 816                                 inode, ceph_ino(inode));
 817                 }
 818                 mapping_set_error(mapping, -EIO);
 819                 return -EIO; /* we're in a forced umount, don't write! */
 820         }
 821         if (fsc->mount_options->wsize < wsize)
 822                 wsize = fsc->mount_options->wsize;
 823
 824         pagevec_init(&pvec);
 825
 826         start_index = wbc->range_cyclic ? mapping->writeback_index : 0;
 827         index = start_index;
 828
 829 retry:
 830         /* find oldest snap context with dirty data */
 831         snapc = get_oldest_context(inode, &ceph_wbc, NULL);
 832         if (!snapc) {
 833                 /* hmm, why does writepages get called when there
 834                    is no dirty data? */
 835                 dout(" no snap context with dirty data?\n");
 836                 goto out;
 837         }
 838         dout(" oldest snapc is %p seq %lld (%d snaps)\n",
 839              snapc, snapc->seq, snapc->num_snaps);
 840
 841         should_loop = false;
 842         if (ceph_wbc.head_snapc && snapc != last_snapc) {
 843                 /* where to start/end? */
 844                 if (wbc->range_cyclic) {
 845                         index = start_index;
 846                         end = -1;
 847                         if (index > 0)
 848                                 should_loop = true;
 849                         dout(" cyclic, start at %lu\n", index);
 850                 } else {
 851                         index = wbc->range_start >> PAGE_SHIFT;
 852                         end = wbc->range_end >> PAGE_SHIFT;
 853                         if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 854                                 range_whole = true;
 855                         dout(" not cyclic, %lu to %lu\n", index, end);
 856                 }
 857         } else if (!ceph_wbc.head_snapc) {
 858                 /* Do not respect wbc->range_{start,end}. Dirty pages
 859                  * in that range can be associated with newer snapc.
 860                  * They are not writeable until we write all dirty pages
 861                  * associated with 'snapc' get written */
 862                 if (index > 0)
 863                         should_loop = true;
 864                 dout(" non-head snapc, range whole\n");
 865         }
 866
 867         ceph_put_snap_context(last_snapc);
 868         last_snapc = snapc;
 869
 870         while (!done && index <= end) {
 871                 int num_ops = 0, op_idx;
 872                 unsigned i, pvec_pages, max_pages, locked_pages = 0;
 873                 struct page **pages = NULL, **data_pages;
 874                 struct page *page;
 875                 pgoff_t strip_unit_end = 0;
 876                 u64 offset = 0, len = 0;
 877                 bool from_pool = false;
 878
 879                 max_pages = wsize >> PAGE_SHIFT;
 880
 881 get_more_pages:
 882                 pvec_pages = pagevec_lookup_range_tag(&pvec, mapping, &index,
 883                                                 end, PAGECACHE_TAG_DIRTY);
 884                 dout("pagevec_lookup_range_tag got %d\n", pvec_pages);
 885                 if (!pvec_pages && !locked_pages)
 886                         break;
 887                 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
 888                         page = pvec.pages[i];
 889                         dout("? %p idx %lu\n", page, page->index);
 890                         if (locked_pages == 0)
 891                                 lock_page(page);  /* first page */
 892                         else if (!trylock_page(page))
 893                                 break;
 894
 895                         /* only dirty pages, or our accounting breaks */
 896                         if (unlikely(!PageDirty(page)) ||
 897                             unlikely(page->mapping != mapping)) {
 898                                 dout("!dirty or !mapping %p\n", page);
 899                                 unlock_page(page);
 900                                 continue;
 901                         }
 902                         /* only if matching snap context */
 903                         pgsnapc = page_snap_context(page);
 904                         if (pgsnapc != snapc) {
 905                                 dout("page snapc %p %lld != oldest %p %lld\n",
 906                                      pgsnapc, pgsnapc->seq, snapc, snapc->seq);
 907                                 if (!should_loop &&
 908                                     !ceph_wbc.head_snapc &&
 909                                     wbc->sync_mode != WB_SYNC_NONE)
 910                                         should_loop = true;
 911                                 unlock_page(page);
 912                                 continue;
 913                         }
 914                         if (page_offset(page) >= ceph_wbc.i_size) {
 915                                 struct folio *folio = page_folio(page);
 916
 917                                 dout("folio at %lu beyond eof %llu\n",
 918                                      folio->index, ceph_wbc.i_size);
 919                                 if ((ceph_wbc.size_stable ||
 920                                     folio_pos(folio) >= i_size_read(inode)) &&
 921                                     folio_clear_dirty_for_io(folio))
 922                                         folio_invalidate(folio, 0,
 923                                                         folio_size(folio));
 924                                 folio_unlock(folio);
 925                                 continue;
 926                         }
 927                         if (strip_unit_end && (page->index > strip_unit_end)) {
 928                                 dout("end of strip unit %p\n", page);
 929                                 unlock_page(page);
 930                                 break;
 931                         }
 932                         if (PageWriteback(page) || PageFsCache(page)) {
 933                                 if (wbc->sync_mode == WB_SYNC_NONE) {
 934                                         dout("%p under writeback\n", page);
 935                                         unlock_page(page);
 936                                         continue;
 937                                 }
 938                                 dout("waiting on writeback %p\n", page);
 939                                 wait_on_page_writeback(page);
 940                                 wait_on_page_fscache(page);
 941                         }
 942
 943                         if (!clear_page_dirty_for_io(page)) {
 944                                 dout("%p !clear_page_dirty_for_io\n", page);
 945                                 unlock_page(page);
 946                                 continue;
 947                         }
 948
 949                         /*
 950                          * We have something to write.  If this is
 951                          * the first locked page this time through,
 952                          * calculate max possinle write size and
 953                          * allocate a page array
 954                          */
 955                         if (locked_pages == 0) {
 956                                 u64 objnum;
 957                                 u64 objoff;
 958                                 u32 xlen;
 959
 960                                 /* prepare async write request */
 961                                 offset = (u64)page_offset(page);
 962                                 ceph_calc_file_object_mapping(&ci->i_layout,
 963                                                               offset, wsize,
 964                                                               &objnum, &objoff,
 965                                                               &xlen);
 966                                 len = xlen;
 967
 968                                 num_ops = 1;
 969                                 strip_unit_end = page->index +
 970                                         ((len - 1) >> PAGE_SHIFT);
 971
 972                                 BUG_ON(pages);
 973                                 max_pages = calc_pages_for(0, (u64)len);
 974                                 pages = kmalloc_array(max_pages,
 975                                                       sizeof(*pages),
 976                                                       GFP_NOFS);
 977                                 if (!pages) {
 978                                         from_pool = true;
 979                                         pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
 980                                         BUG_ON(!pages);
 981                                 }
 982
 983                                 len = 0;
 984                         } else if (page->index !=
 985                                    (offset + len) >> PAGE_SHIFT) {
 986                                 if (num_ops >= (from_pool ?  CEPH_OSD_SLAB_OPS :
 987                                                              CEPH_OSD_MAX_OPS)) {
 988                                         redirty_page_for_writepage(wbc, page);
 989                                         unlock_page(page);
 990                                         break;
 991                                 }
 992
 993                                 num_ops++;
 994                                 offset = (u64)page_offset(page);
 995                                 len = 0;
 996                         }
 997
 998                         /* note position of first page in pvec */
 999                         dout("%p will write page %p idx %lu\n",
1000                              inode, page, page->index);
1001
1002                         if (atomic_long_inc_return(&fsc->writeback_count) >
1003                             CONGESTION_ON_THRESH(
1004                                     fsc->mount_options->congestion_kb))
1005                                 fsc->write_congested = true;
1006
1007                         pages[locked_pages++] = page;
1008                         pvec.pages[i] = NULL;
1009
1010                         len += thp_size(page);
1011                 }
1012
1013                 /* did we get anything? */
1014                 if (!locked_pages)
1015                         goto release_pvec_pages;
1016                 if (i) {
1017                         unsigned j, n = 0;
1018                         /* shift unused page to beginning of pvec */
1019                         for (j = 0; j < pvec_pages; j++) {
1020                                 if (!pvec.pages[j])
1021                                         continue;
1022                                 if (n < j)
1023                                         pvec.pages[n] = pvec.pages[j];
1024                                 n++;
1025                         }
1026                         pvec.nr = n;
1027
1028                         if (pvec_pages && i == pvec_pages &&
1029                             locked_pages < max_pages) {
1030                                 dout("reached end pvec, trying for more\n");
1031                                 pagevec_release(&pvec);
1032                                 goto get_more_pages;
1033                         }
1034                 }
1035
1036 new_request:
1037                 offset = page_offset(pages[0]);
1038                 len = wsize;
1039
1040                 req = ceph_osdc_new_request(&fsc->client->osdc,
1041                                         &ci->i_layout, vino,
1042                                         offset, &len, 0, num_ops,
1043                                         CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1044                                         snapc, ceph_wbc.truncate_seq,
1045                                         ceph_wbc.truncate_size, false);
1046                 if (IS_ERR(req)) {
1047                         req = ceph_osdc_new_request(&fsc->client->osdc,
1048                                                 &ci->i_layout, vino,
1049                                                 offset, &len, 0,
1050                                                 min(num_ops,
1051                                                     CEPH_OSD_SLAB_OPS),
1052                                                 CEPH_OSD_OP_WRITE,
1053                                                 CEPH_OSD_FLAG_WRITE,
1054                                                 snapc, ceph_wbc.truncate_seq,
1055                                                 ceph_wbc.truncate_size, true);
1056                         BUG_ON(IS_ERR(req));
1057                 }
1058                 BUG_ON(len < page_offset(pages[locked_pages - 1]) +
1059                              thp_size(page) - offset);
1060
1061                 req->r_callback = writepages_finish;
1062                 req->r_inode = inode;
1063
1064                 /* Format the osd request message and submit the write */
1065                 len = 0;
1066                 data_pages = pages;
1067                 op_idx = 0;
1068                 for (i = 0; i < locked_pages; i++) {
1069                         u64 cur_offset = page_offset(pages[i]);
1070                         /*
1071                          * Discontinuity in page range? Ceph can handle that by just passing
1072                          * multiple extents in the write op.
1073                          */
1074                         if (offset + len != cur_offset) {
1075                                 /* If it's full, stop here */
1076                                 if (op_idx + 1 == req->r_num_ops)
1077                                         break;
1078
1079                                 /* Kick off an fscache write with what we have so far. */
1080                                 ceph_fscache_write_to_cache(inode, offset, len, caching);
1081
1082                                 /* Start a new extent */
1083                                 osd_req_op_extent_dup_last(req, op_idx,
1084                                                            cur_offset - offset);
1085                                 dout("writepages got pages at %llu~%llu\n",
1086                                      offset, len);
1087                                 osd_req_op_extent_osd_data_pages(req, op_idx,
1088                                                         data_pages, len, 0,
1089                                                         from_pool, false);
1090                                 osd_req_op_extent_update(req, op_idx, len);
1091
1092                                 len = 0;
1093                                 offset = cur_offset;
1094                                 data_pages = pages + i;
1095                                 op_idx++;
1096                         }
1097
1098                         set_page_writeback(pages[i]);
1099                         if (caching)
1100                                 ceph_set_page_fscache(pages[i]);
1101                         len += thp_size(page);
1102                 }
1103                 ceph_fscache_write_to_cache(inode, offset, len, caching);
1104
1105                 if (ceph_wbc.size_stable) {
1106                         len = min(len, ceph_wbc.i_size - offset);
1107                 } else if (i == locked_pages) {
1108                         /* writepages_finish() clears writeback pages
1109                          * according to the data length, so make sure
1110                          * data length covers all locked pages */
1111                         u64 min_len = len + 1 - thp_size(page);
1112                         len = get_writepages_data_length(inode, pages[i - 1],
1113                                                          offset);
1114                         len = max(len, min_len);
1115                 }
1116                 dout("writepages got pages at %llu~%llu\n", offset, len);
1117
1118                 osd_req_op_extent_osd_data_pages(req, op_idx, data_pages, len,
1119                                                  0, from_pool, false);
1120                 osd_req_op_extent_update(req, op_idx, len);
1121
1122                 BUG_ON(op_idx + 1 != req->r_num_ops);
1123
1124                 from_pool = false;
1125                 if (i < locked_pages) {
1126                         BUG_ON(num_ops <= req->r_num_ops);
1127                         num_ops -= req->r_num_ops;
1128                         locked_pages -= i;
1129
1130                         /* allocate new pages array for next request */
1131                         data_pages = pages;
1132                         pages = kmalloc_array(locked_pages, sizeof(*pages),
1133                                               GFP_NOFS);
1134                         if (!pages) {
1135                                 from_pool = true;
1136                                 pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
1137                                 BUG_ON(!pages);
1138                         }
1139                         memcpy(pages, data_pages + i,
1140                                locked_pages * sizeof(*pages));
1141                         memset(data_pages + i, 0,
1142                                locked_pages * sizeof(*pages));
1143                 } else {
1144                         BUG_ON(num_ops != req->r_num_ops);
1145                         index = pages[i - 1]->index + 1;
1146                         /* request message now owns the pages array */
1147                         pages = NULL;
1148                 }
1149
1150                 req->r_mtime = inode->i_mtime;
1151                 ceph_osdc_start_request(&fsc->client->osdc, req);
1152                 req = NULL;
1153
1154                 wbc->nr_to_write -= i;
1155                 if (pages)
1156                         goto new_request;
1157
1158                 /*
1159                  * We stop writing back only if we are not doing
1160                  * integrity sync. In case of integrity sync we have to
1161                  * keep going until we have written all the pages
1162                  * we tagged for writeback prior to entering this loop.
1163                  */
1164                 if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE)
1165                         done = true;
1166
1167 release_pvec_pages:
1168                 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
1169                      pvec.nr ? pvec.pages[0] : NULL);
1170                 pagevec_release(&pvec);
1171         }
1172
1173         if (should_loop && !done) {
1174                 /* more to do; loop back to beginning of file */
1175                 dout("writepages looping back to beginning of file\n");
1176                 end = start_index - 1; /* OK even when start_index == 0 */
1177
1178                 /* to write dirty pages associated with next snapc,
1179                  * we need to wait until current writes complete */
1180                 if (wbc->sync_mode != WB_SYNC_NONE &&
1181                     start_index == 0 && /* all dirty pages were checked */
1182                     !ceph_wbc.head_snapc) {
1183                         struct page *page;
1184                         unsigned i, nr;
1185                         index = 0;
1186                         while ((index <= end) &&
1187                                (nr = pagevec_lookup_tag(&pvec, mapping, &index,
1188                                                 PAGECACHE_TAG_WRITEBACK))) {
1189                                 for (i = 0; i < nr; i++) {
1190                                         page = pvec.pages[i];
1191                                         if (page_snap_context(page) != snapc)
1192                                                 continue;
1193                                         wait_on_page_writeback(page);
1194                                 }
1195                                 pagevec_release(&pvec);
1196                                 cond_resched();
1197                         }
1198                 }
1199
1200                 start_index = 0;
1201                 index = 0;
1202                 goto retry;
1203         }
1204
1205         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1206                 mapping->writeback_index = index;
1207
1208 out:
1209         ceph_osdc_put_request(req);
1210         ceph_put_snap_context(last_snapc);
1211         dout("writepages dend - startone, rc = %d\n", rc);
1212         return rc;
1213 }
1214
1215
1216
1217 /*
1218  * See if a given @snapc is either writeable, or already written.
1219  */
1220 static int context_is_writeable_or_written(struct inode *inode,
1221                                            struct ceph_snap_context *snapc)
1222 {
1223         struct ceph_snap_context *oldest = get_oldest_context(inode, NULL, NULL);
1224         int ret = !oldest || snapc->seq <= oldest->seq;
1225
1226         ceph_put_snap_context(oldest);
1227         return ret;
1228 }
1229
1230 /**
1231  * ceph_find_incompatible - find an incompatible context and return it
1232  * @page: page being dirtied
1233  *
1234  * We are only allowed to write into/dirty a page if the page is
1235  * clean, or already dirty within the same snap context. Returns a
1236  * conflicting context if there is one, NULL if there isn't, or a
1237  * negative error code on other errors.
1238  *
1239  * Must be called with page lock held.
1240  */
1241 static struct ceph_snap_context *
1242 ceph_find_incompatible(struct page *page)
1243 {
1244         struct inode *inode = page->mapping->host;
1245         struct ceph_inode_info *ci = ceph_inode(inode);
1246
1247         if (ceph_inode_is_shutdown(inode)) {
1248                 dout(" page %p %llx:%llx is shutdown\n", page,
1249                      ceph_vinop(inode));
1250                 return ERR_PTR(-ESTALE);
1251         }
1252
1253         for (;;) {
1254                 struct ceph_snap_context *snapc, *oldest;
1255
1256                 wait_on_page_writeback(page);
1257
1258                 snapc = page_snap_context(page);
1259                 if (!snapc || snapc == ci->i_head_snapc)
1260                         break;
1261
1262                 /*
1263                  * this page is already dirty in another (older) snap
1264                  * context!  is it writeable now?
1265                  */
1266                 oldest = get_oldest_context(inode, NULL, NULL);
1267                 if (snapc->seq > oldest->seq) {
1268                         /* not writeable -- return it for the caller to deal with */
1269                         ceph_put_snap_context(oldest);
1270                         dout(" page %p snapc %p not current or oldest\n", page, snapc);
1271                         return ceph_get_snap_context(snapc);
1272                 }
1273                 ceph_put_snap_context(oldest);
1274
1275                 /* yay, writeable, do it now (without dropping page lock) */
1276                 dout(" page %p snapc %p not current, but oldest\n", page, snapc);
1277                 if (clear_page_dirty_for_io(page)) {
1278                         int r = writepage_nounlock(page, NULL);
1279                         if (r < 0)
1280                                 return ERR_PTR(r);
1281                 }
1282         }
1283         return NULL;
1284 }
1285
1286 static int ceph_netfs_check_write_begin(struct file *file, loff_t pos, unsigned int len,
1287                                         struct folio **foliop, void **_fsdata)
1288 {
1289         struct inode *inode = file_inode(file);
1290         struct ceph_inode_info *ci = ceph_inode(inode);
1291         struct ceph_snap_context *snapc;
1292
1293         snapc = ceph_find_incompatible(folio_page(*foliop, 0));
1294         if (snapc) {
1295                 int r;
1296
1297                 folio_unlock(*foliop);
1298                 folio_put(*foliop);
1299                 *foliop = NULL;
1300                 if (IS_ERR(snapc))
1301                         return PTR_ERR(snapc);
1302
1303                 ceph_queue_writeback(inode);
1304                 r = wait_event_killable(ci->i_cap_wq,
1305                                         context_is_writeable_or_written(inode, snapc));
1306                 ceph_put_snap_context(snapc);
1307                 return r == 0 ? -EAGAIN : r;
1308         }
1309         return 0;
1310 }
1311
1312 /*
1313  * We are only allowed to write into/dirty the page if the page is
1314  * clean, or already dirty within the same snap context.
1315  */
1316 static int ceph_write_begin(struct file *file, struct address_space *mapping,
1317                             loff_t pos, unsigned len,
1318                             struct page **pagep, void **fsdata)
1319 {
1320         struct inode *inode = file_inode(file);
1321         struct ceph_inode_info *ci = ceph_inode(inode);
1322         struct folio *folio = NULL;
1323         int r;
1324
1325         r = netfs_write_begin(&ci->netfs, file, inode->i_mapping, pos, len, &folio, NULL);
1326         if (r < 0)
1327                 return r;
1328
1329         folio_wait_fscache(folio);
1330         WARN_ON_ONCE(!folio_test_locked(folio));
1331         *pagep = &folio->page;
1332         return 0;
1333 }
1334
1335 /*
1336  * we don't do anything in here that simple_write_end doesn't do
1337  * except adjust dirty page accounting
1338  */
1339 static int ceph_write_end(struct file *file, struct address_space *mapping,
1340                           loff_t pos, unsigned len, unsigned copied,
1341                           struct page *subpage, void *fsdata)
1342 {
1343         struct folio *folio = page_folio(subpage);
1344         struct inode *inode = file_inode(file);
1345         bool check_cap = false;
1346
1347         dout("write_end file %p inode %p folio %p %d~%d (%d)\n", file,
1348              inode, folio, (int)pos, (int)copied, (int)len);
1349
1350         if (!folio_test_uptodate(folio)) {
1351                 /* just return that nothing was copied on a short copy */
1352                 if (copied < len) {
1353                         copied = 0;
1354                         goto out;
1355                 }
1356                 folio_mark_uptodate(folio);
1357         }
1358
1359         /* did file size increase? */
1360         if (pos+copied > i_size_read(inode))
1361                 check_cap = ceph_inode_set_size(inode, pos+copied);
1362
1363         folio_mark_dirty(folio);
1364
1365 out:
1366         folio_unlock(folio);
1367         folio_put(folio);
1368
1369         if (check_cap)
1370                 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1371
1372         return copied;
1373 }
1374
1375 const struct address_space_operations ceph_aops = {
1376         .read_folio = netfs_read_folio,
1377         .readahead = netfs_readahead,
1378         .writepage = ceph_writepage,
1379         .writepages = ceph_writepages_start,
1380         .write_begin = ceph_write_begin,
1381         .write_end = ceph_write_end,
1382         .dirty_folio = ceph_dirty_folio,
1383         .invalidate_folio = ceph_invalidate_folio,
1384         .release_folio = ceph_release_folio,
1385         .direct_IO = noop_direct_IO,
1386 };
1387
1388 static void ceph_block_sigs(sigset_t *oldset)
1389 {
1390         sigset_t mask;
1391         siginitsetinv(&mask, sigmask(SIGKILL));
1392         sigprocmask(SIG_BLOCK, &mask, oldset);
1393 }
1394
1395 static void ceph_restore_sigs(sigset_t *oldset)
1396 {
1397         sigprocmask(SIG_SETMASK, oldset, NULL);
1398 }
1399
1400 /*
1401  * vm ops
1402  */
1403 static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
1404 {
1405         struct vm_area_struct *vma = vmf->vma;
1406         struct inode *inode = file_inode(vma->vm_file);
1407         struct ceph_inode_info *ci = ceph_inode(inode);
1408         struct ceph_file_info *fi = vma->vm_file->private_data;
1409         loff_t off = (loff_t)vmf->pgoff << PAGE_SHIFT;
1410         int want, got, err;
1411         sigset_t oldset;
1412         vm_fault_t ret = VM_FAULT_SIGBUS;
1413
1414         if (ceph_inode_is_shutdown(inode))
1415                 return ret;
1416
1417         ceph_block_sigs(&oldset);
1418
1419         dout("filemap_fault %p %llx.%llx %llu trying to get caps\n",
1420              inode, ceph_vinop(inode), off);
1421         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1422                 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1423         else
1424                 want = CEPH_CAP_FILE_CACHE;
1425
1426         got = 0;
1427         err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_RD, want, -1, &got);
1428         if (err < 0)
1429                 goto out_restore;
1430
1431         dout("filemap_fault %p %llu got cap refs on %s\n",
1432              inode, off, ceph_cap_string(got));
1433
1434         if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1435             !ceph_has_inline_data(ci)) {
1436                 CEPH_DEFINE_RW_CONTEXT(rw_ctx, got);
1437                 ceph_add_rw_context(fi, &rw_ctx);
1438                 ret = filemap_fault(vmf);
1439                 ceph_del_rw_context(fi, &rw_ctx);
1440                 dout("filemap_fault %p %llu drop cap refs %s ret %x\n",
1441                      inode, off, ceph_cap_string(got), ret);
1442         } else
1443                 err = -EAGAIN;
1444
1445         ceph_put_cap_refs(ci, got);
1446
1447         if (err != -EAGAIN)
1448                 goto out_restore;
1449
1450         /* read inline data */
1451         if (off >= PAGE_SIZE) {
1452                 /* does not support inline data > PAGE_SIZE */
1453                 ret = VM_FAULT_SIGBUS;
1454         } else {
1455                 struct address_space *mapping = inode->i_mapping;
1456                 struct page *page;
1457
1458                 filemap_invalidate_lock_shared(mapping);
1459                 page = find_or_create_page(mapping, 0,
1460                                 mapping_gfp_constraint(mapping, ~__GFP_FS));
1461                 if (!page) {
1462                         ret = VM_FAULT_OOM;
1463                         goto out_inline;
1464                 }
1465                 err = __ceph_do_getattr(inode, page,
1466                                          CEPH_STAT_CAP_INLINE_DATA, true);
1467                 if (err < 0 || off >= i_size_read(inode)) {
1468                         unlock_page(page);
1469                         put_page(page);
1470                         ret = vmf_error(err);
1471                         goto out_inline;
1472                 }
1473                 if (err < PAGE_SIZE)
1474                         zero_user_segment(page, err, PAGE_SIZE);
1475                 else
1476                         flush_dcache_page(page);
1477                 SetPageUptodate(page);
1478                 vmf->page = page;
1479                 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1480 out_inline:
1481                 filemap_invalidate_unlock_shared(mapping);
1482                 dout("filemap_fault %p %llu read inline data ret %x\n",
1483                      inode, off, ret);
1484         }
1485 out_restore:
1486         ceph_restore_sigs(&oldset);
1487         if (err < 0)
1488                 ret = vmf_error(err);
1489
1490         return ret;
1491 }
1492
1493 static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
1494 {
1495         struct vm_area_struct *vma = vmf->vma;
1496         struct inode *inode = file_inode(vma->vm_file);
1497         struct ceph_inode_info *ci = ceph_inode(inode);
1498         struct ceph_file_info *fi = vma->vm_file->private_data;
1499         struct ceph_cap_flush *prealloc_cf;
1500         struct page *page = vmf->page;
1501         loff_t off = page_offset(page);
1502         loff_t size = i_size_read(inode);
1503         size_t len;
1504         int want, got, err;
1505         sigset_t oldset;
1506         vm_fault_t ret = VM_FAULT_SIGBUS;
1507
1508         if (ceph_inode_is_shutdown(inode))
1509                 return ret;
1510
1511         prealloc_cf = ceph_alloc_cap_flush();
1512         if (!prealloc_cf)
1513                 return VM_FAULT_OOM;
1514
1515         sb_start_pagefault(inode->i_sb);
1516         ceph_block_sigs(&oldset);
1517
1518         if (off + thp_size(page) <= size)
1519                 len = thp_size(page);
1520         else
1521                 len = offset_in_thp(page, size);
1522
1523         dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1524              inode, ceph_vinop(inode), off, len, size);
1525         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1526                 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1527         else
1528                 want = CEPH_CAP_FILE_BUFFER;
1529
1530         got = 0;
1531         err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_WR, want, off + len, &got);
1532         if (err < 0)
1533                 goto out_free;
1534
1535         dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1536              inode, off, len, ceph_cap_string(got));
1537
1538         /* Update time before taking page lock */
1539         file_update_time(vma->vm_file);
1540         inode_inc_iversion_raw(inode);
1541
1542         do {
1543                 struct ceph_snap_context *snapc;
1544
1545                 lock_page(page);
1546
1547                 if (page_mkwrite_check_truncate(page, inode) < 0) {
1548                         unlock_page(page);
1549                         ret = VM_FAULT_NOPAGE;
1550                         break;
1551                 }
1552
1553                 snapc = ceph_find_incompatible(page);
1554                 if (!snapc) {
1555                         /* success.  we'll keep the page locked. */
1556                         set_page_dirty(page);
1557                         ret = VM_FAULT_LOCKED;
1558                         break;
1559                 }
1560
1561                 unlock_page(page);
1562
1563                 if (IS_ERR(snapc)) {
1564                         ret = VM_FAULT_SIGBUS;
1565                         break;
1566                 }
1567
1568                 ceph_queue_writeback(inode);
1569                 err = wait_event_killable(ci->i_cap_wq,
1570                                 context_is_writeable_or_written(inode, snapc));
1571                 ceph_put_snap_context(snapc);
1572         } while (err == 0);
1573
1574         if (ret == VM_FAULT_LOCKED) {
1575                 int dirty;
1576                 spin_lock(&ci->i_ceph_lock);
1577                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1578                                                &prealloc_cf);
1579                 spin_unlock(&ci->i_ceph_lock);
1580                 if (dirty)
1581                         __mark_inode_dirty(inode, dirty);
1582         }
1583
1584         dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %x\n",
1585              inode, off, len, ceph_cap_string(got), ret);
1586         ceph_put_cap_refs_async(ci, got);
1587 out_free:
1588         ceph_restore_sigs(&oldset);
1589         sb_end_pagefault(inode->i_sb);
1590         ceph_free_cap_flush(prealloc_cf);
1591         if (err < 0)
1592                 ret = vmf_error(err);
1593         return ret;
1594 }
1595
1596 void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1597                            char *data, size_t len)
1598 {
1599         struct address_space *mapping = inode->i_mapping;
1600         struct page *page;
1601
1602         if (locked_page) {
1603                 page = locked_page;
1604         } else {
1605                 if (i_size_read(inode) == 0)
1606                         return;
1607                 page = find_or_create_page(mapping, 0,
1608                                            mapping_gfp_constraint(mapping,
1609                                            ~__GFP_FS));
1610                 if (!page)
1611                         return;
1612                 if (PageUptodate(page)) {
1613                         unlock_page(page);
1614                         put_page(page);
1615                         return;
1616                 }
1617         }
1618
1619         dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1620              inode, ceph_vinop(inode), len, locked_page);
1621
1622         if (len > 0) {
1623                 void *kaddr = kmap_atomic(page);
1624                 memcpy(kaddr, data, len);
1625                 kunmap_atomic(kaddr);
1626         }
1627
1628         if (page != locked_page) {
1629                 if (len < PAGE_SIZE)
1630                         zero_user_segment(page, len, PAGE_SIZE);
1631                 else
1632                         flush_dcache_page(page);
1633
1634                 SetPageUptodate(page);
1635                 unlock_page(page);
1636                 put_page(page);
1637         }
1638 }
1639
1640 int ceph_uninline_data(struct file *file)
1641 {
1642         struct inode *inode = file_inode(file);
1643         struct ceph_inode_info *ci = ceph_inode(inode);
1644         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1645         struct ceph_osd_request *req = NULL;
1646         struct ceph_cap_flush *prealloc_cf;
1647         struct folio *folio = NULL;
1648         u64 inline_version = CEPH_INLINE_NONE;
1649         struct page *pages[1];
1650         int err = 0;
1651         u64 len;
1652
1653         spin_lock(&ci->i_ceph_lock);
1654         inline_version = ci->i_inline_version;
1655         spin_unlock(&ci->i_ceph_lock);
1656
1657         dout("uninline_data %p %llx.%llx inline_version %llu\n",
1658              inode, ceph_vinop(inode), inline_version);
1659
1660         if (inline_version == CEPH_INLINE_NONE)
1661                 return 0;
1662
1663         prealloc_cf = ceph_alloc_cap_flush();
1664         if (!prealloc_cf)
1665                 return -ENOMEM;
1666
1667         if (inline_version == 1) /* initial version, no data */
1668                 goto out_uninline;
1669
1670         folio = read_mapping_folio(inode->i_mapping, 0, file);
1671         if (IS_ERR(folio)) {
1672                 err = PTR_ERR(folio);
1673                 goto out;
1674         }
1675
1676         folio_lock(folio);
1677
1678         len = i_size_read(inode);
1679         if (len > folio_size(folio))
1680                 len = folio_size(folio);
1681
1682         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1683                                     ceph_vino(inode), 0, &len, 0, 1,
1684                                     CEPH_OSD_OP_CREATE, CEPH_OSD_FLAG_WRITE,
1685                                     NULL, 0, 0, false);
1686         if (IS_ERR(req)) {
1687                 err = PTR_ERR(req);
1688                 goto out_unlock;
1689         }
1690
1691         req->r_mtime = inode->i_mtime;
1692         ceph_osdc_start_request(&fsc->client->osdc, req);
1693         err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1694         ceph_osdc_put_request(req);
1695         if (err < 0)
1696                 goto out_unlock;
1697
1698         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1699                                     ceph_vino(inode), 0, &len, 1, 3,
1700                                     CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1701                                     NULL, ci->i_truncate_seq,
1702                                     ci->i_truncate_size, false);
1703         if (IS_ERR(req)) {
1704                 err = PTR_ERR(req);
1705                 goto out_unlock;
1706         }
1707
1708         pages[0] = folio_page(folio, 0);
1709         osd_req_op_extent_osd_data_pages(req, 1, pages, len, 0, false, false);
1710
1711         {
1712                 __le64 xattr_buf = cpu_to_le64(inline_version);
1713                 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1714                                             "inline_version", &xattr_buf,
1715                                             sizeof(xattr_buf),
1716                                             CEPH_OSD_CMPXATTR_OP_GT,
1717                                             CEPH_OSD_CMPXATTR_MODE_U64);
1718                 if (err)
1719                         goto out_put_req;
1720         }
1721
1722         {
1723                 char xattr_buf[32];
1724                 int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1725                                          "%llu", inline_version);
1726                 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1727                                             "inline_version",
1728                                             xattr_buf, xattr_len, 0, 0);
1729                 if (err)
1730                         goto out_put_req;
1731         }
1732
1733         req->r_mtime = inode->i_mtime;
1734         ceph_osdc_start_request(&fsc->client->osdc, req);
1735         err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1736
1737         ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
1738                                   req->r_end_latency, len, err);
1739
1740 out_uninline:
1741         if (!err) {
1742                 int dirty;
1743
1744                 /* Set to CAP_INLINE_NONE and dirty the caps */
1745                 down_read(&fsc->mdsc->snap_rwsem);
1746                 spin_lock(&ci->i_ceph_lock);
1747                 ci->i_inline_version = CEPH_INLINE_NONE;
1748                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR, &prealloc_cf);
1749                 spin_unlock(&ci->i_ceph_lock);
1750                 up_read(&fsc->mdsc->snap_rwsem);
1751                 if (dirty)
1752                         __mark_inode_dirty(inode, dirty);
1753         }
1754 out_put_req:
1755         ceph_osdc_put_request(req);
1756         if (err == -ECANCELED)
1757                 err = 0;
1758 out_unlock:
1759         if (folio) {
1760                 folio_unlock(folio);
1761                 folio_put(folio);
1762         }
1763 out:
1764         ceph_free_cap_flush(prealloc_cf);
1765         dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1766              inode, ceph_vinop(inode), inline_version, err);
1767         return err;
1768 }
1769
1770 static const struct vm_operations_struct ceph_vmops = {
1771         .fault          = ceph_filemap_fault,
1772         .page_mkwrite   = ceph_page_mkwrite,
1773 };
1774
1775 int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1776 {
1777         struct address_space *mapping = file->f_mapping;
1778
1779         if (!mapping->a_ops->read_folio)
1780                 return -ENOEXEC;
1781         vma->vm_ops = &ceph_vmops;
1782         return 0;
1783 }
1784
1785 enum {
1786         POOL_READ       = 1,
1787         POOL_WRITE      = 2,
1788 };
1789
1790 static int __ceph_pool_perm_get(struct ceph_inode_info *ci,
1791                                 s64 pool, struct ceph_string *pool_ns)
1792 {
1793         struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->netfs.inode);
1794         struct ceph_mds_client *mdsc = fsc->mdsc;
1795         struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1796         struct rb_node **p, *parent;
1797         struct ceph_pool_perm *perm;
1798         struct page **pages;
1799         size_t pool_ns_len;
1800         int err = 0, err2 = 0, have = 0;
1801
1802         down_read(&mdsc->pool_perm_rwsem);
1803         p = &mdsc->pool_perm_tree.rb_node;
1804         while (*p) {
1805                 perm = rb_entry(*p, struct ceph_pool_perm, node);
1806                 if (pool < perm->pool)
1807                         p = &(*p)->rb_left;
1808                 else if (pool > perm->pool)
1809                         p = &(*p)->rb_right;
1810                 else {
1811                         int ret = ceph_compare_string(pool_ns,
1812                                                 perm->pool_ns,
1813                                                 perm->pool_ns_len);
1814                         if (ret < 0)
1815                                 p = &(*p)->rb_left;
1816                         else if (ret > 0)
1817                                 p = &(*p)->rb_right;
1818                         else {
1819                                 have = perm->perm;
1820                                 break;
1821                         }
1822                 }
1823         }
1824         up_read(&mdsc->pool_perm_rwsem);
1825         if (*p)
1826                 goto out;
1827
1828         if (pool_ns)
1829                 dout("__ceph_pool_perm_get pool %lld ns %.*s no perm cached\n",
1830                      pool, (int)pool_ns->len, pool_ns->str);
1831         else
1832                 dout("__ceph_pool_perm_get pool %lld no perm cached\n", pool);
1833
1834         down_write(&mdsc->pool_perm_rwsem);
1835         p = &mdsc->pool_perm_tree.rb_node;
1836         parent = NULL;
1837         while (*p) {
1838                 parent = *p;
1839                 perm = rb_entry(parent, struct ceph_pool_perm, node);
1840                 if (pool < perm->pool)
1841                         p = &(*p)->rb_left;
1842                 else if (pool > perm->pool)
1843                         p = &(*p)->rb_right;
1844                 else {
1845                         int ret = ceph_compare_string(pool_ns,
1846                                                 perm->pool_ns,
1847                                                 perm->pool_ns_len);
1848                         if (ret < 0)
1849                                 p = &(*p)->rb_left;
1850                         else if (ret > 0)
1851                                 p = &(*p)->rb_right;
1852                         else {
1853                                 have = perm->perm;
1854                                 break;
1855                         }
1856                 }
1857         }
1858         if (*p) {
1859                 up_write(&mdsc->pool_perm_rwsem);
1860                 goto out;
1861         }
1862
1863         rd_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1864                                          1, false, GFP_NOFS);
1865         if (!rd_req) {
1866                 err = -ENOMEM;
1867                 goto out_unlock;
1868         }
1869
1870         rd_req->r_flags = CEPH_OSD_FLAG_READ;
1871         osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1872         rd_req->r_base_oloc.pool = pool;
1873         if (pool_ns)
1874                 rd_req->r_base_oloc.pool_ns = ceph_get_string(pool_ns);
1875         ceph_oid_printf(&rd_req->r_base_oid, "%llx.00000000", ci->i_vino.ino);
1876
1877         err = ceph_osdc_alloc_messages(rd_req, GFP_NOFS);
1878         if (err)
1879                 goto out_unlock;
1880
1881         wr_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1882                                          1, false, GFP_NOFS);
1883         if (!wr_req) {
1884                 err = -ENOMEM;
1885                 goto out_unlock;
1886         }
1887
1888         wr_req->r_flags = CEPH_OSD_FLAG_WRITE;
1889         osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
1890         ceph_oloc_copy(&wr_req->r_base_oloc, &rd_req->r_base_oloc);
1891         ceph_oid_copy(&wr_req->r_base_oid, &rd_req->r_base_oid);
1892
1893         err = ceph_osdc_alloc_messages(wr_req, GFP_NOFS);
1894         if (err)
1895                 goto out_unlock;
1896
1897         /* one page should be large enough for STAT data */
1898         pages = ceph_alloc_page_vector(1, GFP_KERNEL);
1899         if (IS_ERR(pages)) {
1900                 err = PTR_ERR(pages);
1901                 goto out_unlock;
1902         }
1903
1904         osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
1905                                      0, false, true);
1906         ceph_osdc_start_request(&fsc->client->osdc, rd_req);
1907
1908         wr_req->r_mtime = ci->netfs.inode.i_mtime;
1909         ceph_osdc_start_request(&fsc->client->osdc, wr_req);
1910
1911         err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
1912         err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
1913
1914         if (err >= 0 || err == -ENOENT)
1915                 have |= POOL_READ;
1916         else if (err != -EPERM) {
1917                 if (err == -EBLOCKLISTED)
1918                         fsc->blocklisted = true;
1919                 goto out_unlock;
1920         }
1921
1922         if (err2 == 0 || err2 == -EEXIST)
1923                 have |= POOL_WRITE;
1924         else if (err2 != -EPERM) {
1925                 if (err2 == -EBLOCKLISTED)
1926                         fsc->blocklisted = true;
1927                 err = err2;
1928                 goto out_unlock;
1929         }
1930
1931         pool_ns_len = pool_ns ? pool_ns->len : 0;
1932         perm = kmalloc(sizeof(*perm) + pool_ns_len + 1, GFP_NOFS);
1933         if (!perm) {
1934                 err = -ENOMEM;
1935                 goto out_unlock;
1936         }
1937
1938         perm->pool = pool;
1939         perm->perm = have;
1940         perm->pool_ns_len = pool_ns_len;
1941         if (pool_ns_len > 0)
1942                 memcpy(perm->pool_ns, pool_ns->str, pool_ns_len);
1943         perm->pool_ns[pool_ns_len] = 0;
1944
1945         rb_link_node(&perm->node, parent, p);
1946         rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
1947         err = 0;
1948 out_unlock:
1949         up_write(&mdsc->pool_perm_rwsem);
1950
1951         ceph_osdc_put_request(rd_req);
1952         ceph_osdc_put_request(wr_req);
1953 out:
1954         if (!err)
1955                 err = have;
1956         if (pool_ns)
1957                 dout("__ceph_pool_perm_get pool %lld ns %.*s result = %d\n",
1958                      pool, (int)pool_ns->len, pool_ns->str, err);
1959         else
1960                 dout("__ceph_pool_perm_get pool %lld result = %d\n", pool, err);
1961         return err;
1962 }
1963
1964 int ceph_pool_perm_check(struct inode *inode, int need)
1965 {
1966         struct ceph_inode_info *ci = ceph_inode(inode);
1967         struct ceph_string *pool_ns;
1968         s64 pool;
1969         int ret, flags;
1970
1971         /* Only need to do this for regular files */
1972         if (!S_ISREG(inode->i_mode))
1973                 return 0;
1974
1975         if (ci->i_vino.snap != CEPH_NOSNAP) {
1976                 /*
1977                  * Pool permission check needs to write to the first object.
1978                  * But for snapshot, head of the first object may have alread
1979                  * been deleted. Skip check to avoid creating orphan object.
1980                  */
1981                 return 0;
1982         }
1983
1984         if (ceph_test_mount_opt(ceph_inode_to_client(inode),
1985                                 NOPOOLPERM))
1986                 return 0;
1987
1988         spin_lock(&ci->i_ceph_lock);
1989         flags = ci->i_ceph_flags;
1990         pool = ci->i_layout.pool_id;
1991         spin_unlock(&ci->i_ceph_lock);
1992 check:
1993         if (flags & CEPH_I_POOL_PERM) {
1994                 if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
1995                         dout("ceph_pool_perm_check pool %lld no read perm\n",
1996                              pool);
1997                         return -EPERM;
1998                 }
1999                 if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
2000                         dout("ceph_pool_perm_check pool %lld no write perm\n",
2001                              pool);
2002                         return -EPERM;
2003                 }
2004                 return 0;
2005         }
2006
2007         pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
2008         ret = __ceph_pool_perm_get(ci, pool, pool_ns);
2009         ceph_put_string(pool_ns);
2010         if (ret < 0)
2011                 return ret;
2012
2013         flags = CEPH_I_POOL_PERM;
2014         if (ret & POOL_READ)
2015                 flags |= CEPH_I_POOL_RD;
2016         if (ret & POOL_WRITE)
2017                 flags |= CEPH_I_POOL_WR;
2018
2019         spin_lock(&ci->i_ceph_lock);
2020         if (pool == ci->i_layout.pool_id &&
2021             pool_ns == rcu_dereference_raw(ci->i_layout.pool_ns)) {
2022                 ci->i_ceph_flags |= flags;
2023         } else {
2024                 pool = ci->i_layout.pool_id;
2025                 flags = ci->i_ceph_flags;
2026         }
2027         spin_unlock(&ci->i_ceph_lock);
2028         goto check;
2029 }
2030
2031 void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
2032 {
2033         struct ceph_pool_perm *perm;
2034         struct rb_node *n;
2035
2036         while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
2037                 n = rb_first(&mdsc->pool_perm_tree);
2038                 perm = rb_entry(n, struct ceph_pool_perm, node);
2039                 rb_erase(n, &mdsc->pool_perm_tree);
2040                 kfree(perm);
2041         }
2042 }