linux/fs/ceph/addr.c
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   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/pagemap.h>
   8#include <linux/writeback.h>    /* generic_writepages */
   9#include <linux/slab.h>
  10#include <linux/pagevec.h>
  11#include <linux/task_io_accounting_ops.h>
  12#include <linux/signal.h>
  13
  14#include "super.h"
  15#include "mds_client.h"
  16#include "cache.h"
  17#include <linux/ceph/osd_client.h>
  18#include <linux/ceph/striper.h>
  19
  20/*
  21 * Ceph address space ops.
  22 *
  23 * There are a few funny things going on here.
  24 *
  25 * The page->private field is used to reference a struct
  26 * ceph_snap_context for _every_ dirty page.  This indicates which
  27 * snapshot the page was logically dirtied in, and thus which snap
  28 * context needs to be associated with the osd write during writeback.
  29 *
  30 * Similarly, struct ceph_inode_info maintains a set of counters to
  31 * count dirty pages on the inode.  In the absence of snapshots,
  32 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
  33 *
  34 * When a snapshot is taken (that is, when the client receives
  35 * notification that a snapshot was taken), each inode with caps and
  36 * with dirty pages (dirty pages implies there is a cap) gets a new
  37 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
  38 * order, new snaps go to the tail).  The i_wrbuffer_ref_head count is
  39 * moved to capsnap->dirty. (Unless a sync write is currently in
  40 * progress.  In that case, the capsnap is said to be "pending", new
  41 * writes cannot start, and the capsnap isn't "finalized" until the
  42 * write completes (or fails) and a final size/mtime for the inode for
  43 * that snap can be settled upon.)  i_wrbuffer_ref_head is reset to 0.
  44 *
  45 * On writeback, we must submit writes to the osd IN SNAP ORDER.  So,
  46 * we look for the first capsnap in i_cap_snaps and write out pages in
  47 * that snap context _only_.  Then we move on to the next capsnap,
  48 * eventually reaching the "live" or "head" context (i.e., pages that
  49 * are not yet snapped) and are writing the most recently dirtied
  50 * pages.
  51 *
  52 * Invalidate and so forth must take care to ensure the dirty page
  53 * accounting is preserved.
  54 */
  55
  56#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
  57#define CONGESTION_OFF_THRESH(congestion_kb)                            \
  58        (CONGESTION_ON_THRESH(congestion_kb) -                          \
  59         (CONGESTION_ON_THRESH(congestion_kb) >> 2))
  60
  61static inline struct ceph_snap_context *page_snap_context(struct page *page)
  62{
  63        if (PagePrivate(page))
  64                return (void *)page->private;
  65        return NULL;
  66}
  67
  68/*
  69 * Dirty a page.  Optimistically adjust accounting, on the assumption
  70 * that we won't race with invalidate.  If we do, readjust.
  71 */
  72static int ceph_set_page_dirty(struct page *page)
  73{
  74        struct address_space *mapping = page->mapping;
  75        struct inode *inode;
  76        struct ceph_inode_info *ci;
  77        struct ceph_snap_context *snapc;
  78        int ret;
  79
  80        if (unlikely(!mapping))
  81                return !TestSetPageDirty(page);
  82
  83        if (PageDirty(page)) {
  84                dout("%p set_page_dirty %p idx %lu -- already dirty\n",
  85                     mapping->host, page, page->index);
  86                BUG_ON(!PagePrivate(page));
  87                return 0;
  88        }
  89
  90        inode = mapping->host;
  91        ci = ceph_inode(inode);
  92
  93        /* dirty the head */
  94        spin_lock(&ci->i_ceph_lock);
  95        BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
  96        if (__ceph_have_pending_cap_snap(ci)) {
  97                struct ceph_cap_snap *capsnap =
  98                                list_last_entry(&ci->i_cap_snaps,
  99                                                struct ceph_cap_snap,
 100                                                ci_item);
 101                snapc = ceph_get_snap_context(capsnap->context);
 102                capsnap->dirty_pages++;
 103        } else {
 104                BUG_ON(!ci->i_head_snapc);
 105                snapc = ceph_get_snap_context(ci->i_head_snapc);
 106                ++ci->i_wrbuffer_ref_head;
 107        }
 108        if (ci->i_wrbuffer_ref == 0)
 109                ihold(inode);
 110        ++ci->i_wrbuffer_ref;
 111        dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
 112             "snapc %p seq %lld (%d snaps)\n",
 113             mapping->host, page, page->index,
 114             ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
 115             ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
 116             snapc, snapc->seq, snapc->num_snaps);
 117        spin_unlock(&ci->i_ceph_lock);
 118
 119        /*
 120         * Reference snap context in page->private.  Also set
 121         * PagePrivate so that we get invalidatepage callback.
 122         */
 123        BUG_ON(PagePrivate(page));
 124        page->private = (unsigned long)snapc;
 125        SetPagePrivate(page);
 126
 127        ret = __set_page_dirty_nobuffers(page);
 128        WARN_ON(!PageLocked(page));
 129        WARN_ON(!page->mapping);
 130
 131        return ret;
 132}
 133
 134/*
 135 * If we are truncating the full page (i.e. offset == 0), adjust the
 136 * dirty page counters appropriately.  Only called if there is private
 137 * data on the page.
 138 */
 139static void ceph_invalidatepage(struct page *page, unsigned int offset,
 140                                unsigned int length)
 141{
 142        struct inode *inode;
 143        struct ceph_inode_info *ci;
 144        struct ceph_snap_context *snapc = page_snap_context(page);
 145
 146        inode = page->mapping->host;
 147        ci = ceph_inode(inode);
 148
 149        if (offset != 0 || length != PAGE_SIZE) {
 150                dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
 151                     inode, page, page->index, offset, length);
 152                return;
 153        }
 154
 155        ceph_invalidate_fscache_page(inode, page);
 156
 157        WARN_ON(!PageLocked(page));
 158        if (!PagePrivate(page))
 159                return;
 160
 161        ClearPageChecked(page);
 162
 163        dout("%p invalidatepage %p idx %lu full dirty page\n",
 164             inode, page, page->index);
 165
 166        ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 167        ceph_put_snap_context(snapc);
 168        page->private = 0;
 169        ClearPagePrivate(page);
 170}
 171
 172static int ceph_releasepage(struct page *page, gfp_t g)
 173{
 174        dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
 175             page, page->index, PageDirty(page) ? "" : "not ");
 176
 177        /* Can we release the page from the cache? */
 178        if (!ceph_release_fscache_page(page, g))
 179                return 0;
 180
 181        return !PagePrivate(page);
 182}
 183
 184/*
 185 * read a single page, without unlocking it.
 186 */
 187static int ceph_do_readpage(struct file *filp, struct page *page)
 188{
 189        struct inode *inode = file_inode(filp);
 190        struct ceph_inode_info *ci = ceph_inode(inode);
 191        struct ceph_osd_client *osdc =
 192                &ceph_inode_to_client(inode)->client->osdc;
 193        int err = 0;
 194        u64 off = page_offset(page);
 195        u64 len = PAGE_SIZE;
 196
 197        if (off >= i_size_read(inode)) {
 198                zero_user_segment(page, 0, PAGE_SIZE);
 199                SetPageUptodate(page);
 200                return 0;
 201        }
 202
 203        if (ci->i_inline_version != CEPH_INLINE_NONE) {
 204                /*
 205                 * Uptodate inline data should have been added
 206                 * into page cache while getting Fcr caps.
 207                 */
 208                if (off == 0)
 209                        return -EINVAL;
 210                zero_user_segment(page, 0, PAGE_SIZE);
 211                SetPageUptodate(page);
 212                return 0;
 213        }
 214
 215        err = ceph_readpage_from_fscache(inode, page);
 216        if (err == 0)
 217                return -EINPROGRESS;
 218
 219        dout("readpage inode %p file %p page %p index %lu\n",
 220             inode, filp, page, page->index);
 221        err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
 222                                  off, &len,
 223                                  ci->i_truncate_seq, ci->i_truncate_size,
 224                                  &page, 1, 0);
 225        if (err == -ENOENT)
 226                err = 0;
 227        if (err < 0) {
 228                SetPageError(page);
 229                ceph_fscache_readpage_cancel(inode, page);
 230                goto out;
 231        }
 232        if (err < PAGE_SIZE)
 233                /* zero fill remainder of page */
 234                zero_user_segment(page, err, PAGE_SIZE);
 235        else
 236                flush_dcache_page(page);
 237
 238        SetPageUptodate(page);
 239        ceph_readpage_to_fscache(inode, page);
 240
 241out:
 242        return err < 0 ? err : 0;
 243}
 244
 245static int ceph_readpage(struct file *filp, struct page *page)
 246{
 247        int r = ceph_do_readpage(filp, page);
 248        if (r != -EINPROGRESS)
 249                unlock_page(page);
 250        else
 251                r = 0;
 252        return r;
 253}
 254
 255/*
 256 * Finish an async read(ahead) op.
 257 */
 258static void finish_read(struct ceph_osd_request *req)
 259{
 260        struct inode *inode = req->r_inode;
 261        struct ceph_osd_data *osd_data;
 262        int rc = req->r_result <= 0 ? req->r_result : 0;
 263        int bytes = req->r_result >= 0 ? req->r_result : 0;
 264        int num_pages;
 265        int i;
 266
 267        dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
 268
 269        /* unlock all pages, zeroing any data we didn't read */
 270        osd_data = osd_req_op_extent_osd_data(req, 0);
 271        BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 272        num_pages = calc_pages_for((u64)osd_data->alignment,
 273                                        (u64)osd_data->length);
 274        for (i = 0; i < num_pages; i++) {
 275                struct page *page = osd_data->pages[i];
 276
 277                if (rc < 0 && rc != -ENOENT) {
 278                        ceph_fscache_readpage_cancel(inode, page);
 279                        goto unlock;
 280                }
 281                if (bytes < (int)PAGE_SIZE) {
 282                        /* zero (remainder of) page */
 283                        int s = bytes < 0 ? 0 : bytes;
 284                        zero_user_segment(page, s, PAGE_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);
 291unlock:
 292                unlock_page(page);
 293                put_page(page);
 294                bytes -= PAGE_SIZE;
 295        }
 296        kfree(osd_data->pages);
 297}
 298
 299/*
 300 * start an async read(ahead) operation.  return nr_pages we submitted
 301 * a read for on success, or negative error code.
 302 */
 303static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 304                      struct list_head *page_list, int max)
 305{
 306        struct ceph_osd_client *osdc =
 307                &ceph_inode_to_client(inode)->client->osdc;
 308        struct ceph_inode_info *ci = ceph_inode(inode);
 309        struct page *page = lru_to_page(page_list);
 310        struct ceph_vino vino;
 311        struct ceph_osd_request *req;
 312        u64 off;
 313        u64 len;
 314        int i;
 315        struct page **pages;
 316        pgoff_t next_index;
 317        int nr_pages = 0;
 318        int got = 0;
 319        int ret = 0;
 320
 321        if (!rw_ctx) {
 322                /* caller of readpages does not hold buffer and read caps
 323                 * (fadvise, madvise and readahead cases) */
 324                int want = CEPH_CAP_FILE_CACHE;
 325                ret = ceph_try_get_caps(ci, CEPH_CAP_FILE_RD, want, true, &got);
 326                if (ret < 0) {
 327                        dout("start_read %p, error getting cap\n", inode);
 328                } else if (!(got & want)) {
 329                        dout("start_read %p, no cache cap\n", inode);
 330                        ret = 0;
 331                }
 332                if (ret <= 0) {
 333                        if (got)
 334                                ceph_put_cap_refs(ci, got);
 335                        while (!list_empty(page_list)) {
 336                                page = lru_to_page(page_list);
 337                                list_del(&page->lru);
 338                                put_page(page);
 339                        }
 340                        return ret;
 341                }
 342        }
 343
 344        off = (u64) page_offset(page);
 345
 346        /* count pages */
 347        next_index = page->index;
 348        list_for_each_entry_reverse(page, page_list, lru) {
 349                if (page->index != next_index)
 350                        break;
 351                nr_pages++;
 352                next_index++;
 353                if (max && nr_pages == max)
 354                        break;
 355        }
 356        len = nr_pages << PAGE_SHIFT;
 357        dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
 358             off, len);
 359        vino = ceph_vino(inode);
 360        req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
 361                                    0, 1, CEPH_OSD_OP_READ,
 362                                    CEPH_OSD_FLAG_READ, NULL,
 363                                    ci->i_truncate_seq, ci->i_truncate_size,
 364                                    false);
 365        if (IS_ERR(req)) {
 366                ret = PTR_ERR(req);
 367                goto out;
 368        }
 369
 370        /* build page vector */
 371        nr_pages = calc_pages_for(0, len);
 372        pages = kmalloc_array(nr_pages, sizeof(*pages), GFP_KERNEL);
 373        if (!pages) {
 374                ret = -ENOMEM;
 375                goto out_put;
 376        }
 377        for (i = 0; i < nr_pages; ++i) {
 378                page = list_entry(page_list->prev, struct page, lru);
 379                BUG_ON(PageLocked(page));
 380                list_del(&page->lru);
 381
 382                dout("start_read %p adding %p idx %lu\n", inode, page,
 383                     page->index);
 384                if (add_to_page_cache_lru(page, &inode->i_data, page->index,
 385                                          GFP_KERNEL)) {
 386                        ceph_fscache_uncache_page(inode, page);
 387                        put_page(page);
 388                        dout("start_read %p add_to_page_cache failed %p\n",
 389                             inode, page);
 390                        nr_pages = i;
 391                        if (nr_pages > 0) {
 392                                len = nr_pages << PAGE_SHIFT;
 393                                osd_req_op_extent_update(req, 0, len);
 394                                break;
 395                        }
 396                        goto out_pages;
 397                }
 398                pages[i] = page;
 399        }
 400        osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
 401        req->r_callback = finish_read;
 402        req->r_inode = inode;
 403
 404        dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
 405        ret = ceph_osdc_start_request(osdc, req, false);
 406        if (ret < 0)
 407                goto out_pages;
 408        ceph_osdc_put_request(req);
 409
 410        /* After adding locked pages to page cache, the inode holds cache cap.
 411         * So we can drop our cap refs. */
 412        if (got)
 413                ceph_put_cap_refs(ci, got);
 414
 415        return nr_pages;
 416
 417out_pages:
 418        for (i = 0; i < nr_pages; ++i) {
 419                ceph_fscache_readpage_cancel(inode, pages[i]);
 420                unlock_page(pages[i]);
 421        }
 422        ceph_put_page_vector(pages, nr_pages, false);
 423out_put:
 424        ceph_osdc_put_request(req);
 425out:
 426        if (got)
 427                ceph_put_cap_refs(ci, got);
 428        return ret;
 429}
 430
 431
 432/*
 433 * Read multiple pages.  Leave pages we don't read + unlock in page_list;
 434 * the caller (VM) cleans them up.
 435 */
 436static int ceph_readpages(struct file *file, struct address_space *mapping,
 437                          struct list_head *page_list, unsigned nr_pages)
 438{
 439        struct inode *inode = file_inode(file);
 440        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 441        struct ceph_file_info *fi = file->private_data;
 442        struct ceph_rw_context *rw_ctx;
 443        int rc = 0;
 444        int max = 0;
 445
 446        if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
 447                return -EINVAL;
 448
 449        rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
 450                                         &nr_pages);
 451
 452        if (rc == 0)
 453                goto out;
 454
 455        rw_ctx = ceph_find_rw_context(fi);
 456        max = fsc->mount_options->rsize >> PAGE_SHIFT;
 457        dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
 458             inode, file, rw_ctx, nr_pages, max);
 459        while (!list_empty(page_list)) {
 460                rc = start_read(inode, rw_ctx, page_list, max);
 461                if (rc < 0)
 462                        goto out;
 463        }
 464out:
 465        ceph_fscache_readpages_cancel(inode, page_list);
 466
 467        dout("readpages %p file %p ret %d\n", inode, file, rc);
 468        return rc;
 469}
 470
 471struct ceph_writeback_ctl
 472{
 473        loff_t i_size;
 474        u64 truncate_size;
 475        u32 truncate_seq;
 476        bool size_stable;
 477        bool head_snapc;
 478};
 479
 480/*
 481 * Get ref for the oldest snapc for an inode with dirty data... that is, the
 482 * only snap context we are allowed to write back.
 483 */
 484static struct ceph_snap_context *
 485get_oldest_context(struct inode *inode, struct ceph_writeback_ctl *ctl,
 486                   struct ceph_snap_context *page_snapc)
 487{
 488        struct ceph_inode_info *ci = ceph_inode(inode);
 489        struct ceph_snap_context *snapc = NULL;
 490        struct ceph_cap_snap *capsnap = NULL;
 491
 492        spin_lock(&ci->i_ceph_lock);
 493        list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 494                dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
 495                     capsnap->context, capsnap->dirty_pages);
 496                if (!capsnap->dirty_pages)
 497                        continue;
 498
 499                /* get i_size, truncate_{seq,size} for page_snapc? */
 500                if (snapc && capsnap->context != page_snapc)
 501                        continue;
 502
 503                if (ctl) {
 504                        if (capsnap->writing) {
 505                                ctl->i_size = i_size_read(inode);
 506                                ctl->size_stable = false;
 507                        } else {
 508                                ctl->i_size = capsnap->size;
 509                                ctl->size_stable = true;
 510                        }
 511                        ctl->truncate_size = capsnap->truncate_size;
 512                        ctl->truncate_seq = capsnap->truncate_seq;
 513                        ctl->head_snapc = false;
 514                }
 515
 516                if (snapc)
 517                        break;
 518
 519                snapc = ceph_get_snap_context(capsnap->context);
 520                if (!page_snapc ||
 521                    page_snapc == snapc ||
 522                    page_snapc->seq > snapc->seq)
 523                        break;
 524        }
 525        if (!snapc && ci->i_wrbuffer_ref_head) {
 526                snapc = ceph_get_snap_context(ci->i_head_snapc);
 527                dout(" head snapc %p has %d dirty pages\n",
 528                     snapc, ci->i_wrbuffer_ref_head);
 529                if (ctl) {
 530                        ctl->i_size = i_size_read(inode);
 531                        ctl->truncate_size = ci->i_truncate_size;
 532                        ctl->truncate_seq = ci->i_truncate_seq;
 533                        ctl->size_stable = false;
 534                        ctl->head_snapc = true;
 535                }
 536        }
 537        spin_unlock(&ci->i_ceph_lock);
 538        return snapc;
 539}
 540
 541static u64 get_writepages_data_length(struct inode *inode,
 542                                      struct page *page, u64 start)
 543{
 544        struct ceph_inode_info *ci = ceph_inode(inode);
 545        struct ceph_snap_context *snapc = page_snap_context(page);
 546        struct ceph_cap_snap *capsnap = NULL;
 547        u64 end = i_size_read(inode);
 548
 549        if (snapc != ci->i_head_snapc) {
 550                bool found = false;
 551                spin_lock(&ci->i_ceph_lock);
 552                list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 553                        if (capsnap->context == snapc) {
 554                                if (!capsnap->writing)
 555                                        end = capsnap->size;
 556                                found = true;
 557                                break;
 558                        }
 559                }
 560                spin_unlock(&ci->i_ceph_lock);
 561                WARN_ON(!found);
 562        }
 563        if (end > page_offset(page) + PAGE_SIZE)
 564                end = page_offset(page) + PAGE_SIZE;
 565        return end > start ? end - start : 0;
 566}
 567
 568/*
 569 * Write a single page, but leave the page locked.
 570 *
 571 * If we get a write error, set the page error bit, but still adjust the
 572 * dirty page accounting (i.e., page is no longer dirty).
 573 */
 574static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 575{
 576        struct inode *inode;
 577        struct ceph_inode_info *ci;
 578        struct ceph_fs_client *fsc;
 579        struct ceph_snap_context *snapc, *oldest;
 580        loff_t page_off = page_offset(page);
 581        int err, len = PAGE_SIZE;
 582        struct ceph_writeback_ctl ceph_wbc;
 583
 584        dout("writepage %p idx %lu\n", page, page->index);
 585
 586        inode = page->mapping->host;
 587        ci = ceph_inode(inode);
 588        fsc = ceph_inode_to_client(inode);
 589
 590        /* verify this is a writeable snap context */
 591        snapc = page_snap_context(page);
 592        if (!snapc) {
 593                dout("writepage %p page %p not dirty?\n", inode, page);
 594                return 0;
 595        }
 596        oldest = get_oldest_context(inode, &ceph_wbc, snapc);
 597        if (snapc->seq > oldest->seq) {
 598                dout("writepage %p page %p snapc %p not writeable - noop\n",
 599                     inode, page, snapc);
 600                /* we should only noop if called by kswapd */
 601                WARN_ON(!(current->flags & PF_MEMALLOC));
 602                ceph_put_snap_context(oldest);
 603                redirty_page_for_writepage(wbc, page);
 604                return 0;
 605        }
 606        ceph_put_snap_context(oldest);
 607
 608        /* is this a partial page at end of file? */
 609        if (page_off >= ceph_wbc.i_size) {
 610                dout("%p page eof %llu\n", page, ceph_wbc.i_size);
 611                page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
 612                return 0;
 613        }
 614
 615        if (ceph_wbc.i_size < page_off + len)
 616                len = ceph_wbc.i_size - page_off;
 617
 618        dout("writepage %p page %p index %lu on %llu~%u snapc %p seq %lld\n",
 619             inode, page, page->index, page_off, len, snapc, snapc->seq);
 620
 621        if (atomic_long_inc_return(&fsc->writeback_count) >
 622            CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
 623                set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
 624
 625        set_page_writeback(page);
 626        err = ceph_osdc_writepages(&fsc->client->osdc, ceph_vino(inode),
 627                                   &ci->i_layout, snapc, page_off, len,
 628                                   ceph_wbc.truncate_seq,
 629                                   ceph_wbc.truncate_size,
 630                                   &inode->i_mtime, &page, 1);
 631        if (err < 0) {
 632                struct writeback_control tmp_wbc;
 633                if (!wbc)
 634                        wbc = &tmp_wbc;
 635                if (err == -ERESTARTSYS) {
 636                        /* killed by SIGKILL */
 637                        dout("writepage interrupted page %p\n", page);
 638                        redirty_page_for_writepage(wbc, page);
 639                        end_page_writeback(page);
 640                        return err;
 641                }
 642                dout("writepage setting page/mapping error %d %p\n",
 643                     err, page);
 644                SetPageError(page);
 645                mapping_set_error(&inode->i_data, err);
 646                wbc->pages_skipped++;
 647        } else {
 648                dout("writepage cleaned page %p\n", page);
 649                err = 0;  /* vfs expects us to return 0 */
 650        }
 651        page->private = 0;
 652        ClearPagePrivate(page);
 653        end_page_writeback(page);
 654        ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 655        ceph_put_snap_context(snapc);  /* page's reference */
 656
 657        if (atomic_long_dec_return(&fsc->writeback_count) <
 658            CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
 659                clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
 660
 661        return err;
 662}
 663
 664static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 665{
 666        int err;
 667        struct inode *inode = page->mapping->host;
 668        BUG_ON(!inode);
 669        ihold(inode);
 670        err = writepage_nounlock(page, wbc);
 671        if (err == -ERESTARTSYS) {
 672                /* direct memory reclaimer was killed by SIGKILL. return 0
 673                 * to prevent caller from setting mapping/page error */
 674                err = 0;
 675        }
 676        unlock_page(page);
 677        iput(inode);
 678        return err;
 679}
 680
 681/*
 682 * lame release_pages helper.  release_pages() isn't exported to
 683 * modules.
 684 */
 685static void ceph_release_pages(struct page **pages, int num)
 686{
 687        struct pagevec pvec;
 688        int i;
 689
 690        pagevec_init(&pvec);
 691        for (i = 0; i < num; i++) {
 692                if (pagevec_add(&pvec, pages[i]) == 0)
 693                        pagevec_release(&pvec);
 694        }
 695        pagevec_release(&pvec);
 696}
 697
 698/*
 699 * async writeback completion handler.
 700 *
 701 * If we get an error, set the mapping error bit, but not the individual
 702 * page error bits.
 703 */
 704static void writepages_finish(struct ceph_osd_request *req)
 705{
 706        struct inode *inode = req->r_inode;
 707        struct ceph_inode_info *ci = ceph_inode(inode);
 708        struct ceph_osd_data *osd_data;
 709        struct page *page;
 710        int num_pages, total_pages = 0;
 711        int i, j;
 712        int rc = req->r_result;
 713        struct ceph_snap_context *snapc = req->r_snapc;
 714        struct address_space *mapping = inode->i_mapping;
 715        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 716        bool remove_page;
 717
 718        dout("writepages_finish %p rc %d\n", inode, rc);
 719        if (rc < 0) {
 720                mapping_set_error(mapping, rc);
 721                ceph_set_error_write(ci);
 722        } else {
 723                ceph_clear_error_write(ci);
 724        }
 725
 726        /*
 727         * We lost the cache cap, need to truncate the page before
 728         * it is unlocked, otherwise we'd truncate it later in the
 729         * page truncation thread, possibly losing some data that
 730         * raced its way in
 731         */
 732        remove_page = !(ceph_caps_issued(ci) &
 733                        (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO));
 734
 735        /* clean all pages */
 736        for (i = 0; i < req->r_num_ops; i++) {
 737                if (req->r_ops[i].op != CEPH_OSD_OP_WRITE)
 738                        break;
 739
 740                osd_data = osd_req_op_extent_osd_data(req, i);
 741                BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 742                num_pages = calc_pages_for((u64)osd_data->alignment,
 743                                           (u64)osd_data->length);
 744                total_pages += num_pages;
 745                for (j = 0; j < num_pages; j++) {
 746                        page = osd_data->pages[j];
 747                        BUG_ON(!page);
 748                        WARN_ON(!PageUptodate(page));
 749
 750                        if (atomic_long_dec_return(&fsc->writeback_count) <
 751                             CONGESTION_OFF_THRESH(
 752                                        fsc->mount_options->congestion_kb))
 753                                clear_bdi_congested(inode_to_bdi(inode),
 754                                                    BLK_RW_ASYNC);
 755
 756                        ceph_put_snap_context(page_snap_context(page));
 757                        page->private = 0;
 758                        ClearPagePrivate(page);
 759                        dout("unlocking %p\n", page);
 760                        end_page_writeback(page);
 761
 762                        if (remove_page)
 763                                generic_error_remove_page(inode->i_mapping,
 764                                                          page);
 765
 766                        unlock_page(page);
 767                }
 768                dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
 769                     inode, osd_data->length, rc >= 0 ? num_pages : 0);
 770
 771                ceph_release_pages(osd_data->pages, num_pages);
 772        }
 773
 774        ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
 775
 776        osd_data = osd_req_op_extent_osd_data(req, 0);
 777        if (osd_data->pages_from_pool)
 778                mempool_free(osd_data->pages,
 779                             ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
 780        else
 781                kfree(osd_data->pages);
 782        ceph_osdc_put_request(req);
 783}
 784
 785/*
 786 * initiate async writeback
 787 */
 788static int ceph_writepages_start(struct address_space *mapping,
 789                                 struct writeback_control *wbc)
 790{
 791        struct inode *inode = mapping->host;
 792        struct ceph_inode_info *ci = ceph_inode(inode);
 793        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 794        struct ceph_vino vino = ceph_vino(inode);
 795        pgoff_t index, start_index, end = -1;
 796        struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
 797        struct pagevec pvec;
 798        int rc = 0;
 799        unsigned int wsize = i_blocksize(inode);
 800        struct ceph_osd_request *req = NULL;
 801        struct ceph_writeback_ctl ceph_wbc;
 802        bool should_loop, range_whole = false;
 803        bool done = false;
 804
 805        dout("writepages_start %p (mode=%s)\n", inode,
 806             wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
 807             (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
 808
 809        if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
 810                if (ci->i_wrbuffer_ref > 0) {
 811                        pr_warn_ratelimited(
 812                                "writepage_start %p %lld forced umount\n",
 813                                inode, ceph_ino(inode));
 814                }
 815                mapping_set_error(mapping, -EIO);
 816                return -EIO; /* we're in a forced umount, don't write! */
 817        }
 818        if (fsc->mount_options->wsize < wsize)
 819                wsize = fsc->mount_options->wsize;
 820
 821        pagevec_init(&pvec);
 822
 823        start_index = wbc->range_cyclic ? mapping->writeback_index : 0;
 824        index = start_index;
 825
 826retry:
 827        /* find oldest snap context with dirty data */
 828        snapc = get_oldest_context(inode, &ceph_wbc, NULL);
 829        if (!snapc) {
 830                /* hmm, why does writepages get called when there
 831                   is no dirty data? */
 832                dout(" no snap context with dirty data?\n");
 833                goto out;
 834        }
 835        dout(" oldest snapc is %p seq %lld (%d snaps)\n",
 836             snapc, snapc->seq, snapc->num_snaps);
 837
 838        should_loop = false;
 839        if (ceph_wbc.head_snapc && snapc != last_snapc) {
 840                /* where to start/end? */
 841                if (wbc->range_cyclic) {
 842                        index = start_index;
 843                        end = -1;
 844                        if (index > 0)
 845                                should_loop = true;
 846                        dout(" cyclic, start at %lu\n", index);
 847                } else {
 848                        index = wbc->range_start >> PAGE_SHIFT;
 849                        end = wbc->range_end >> PAGE_SHIFT;
 850                        if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 851                                range_whole = true;
 852                        dout(" not cyclic, %lu to %lu\n", index, end);
 853                }
 854        } else if (!ceph_wbc.head_snapc) {
 855                /* Do not respect wbc->range_{start,end}. Dirty pages
 856                 * in that range can be associated with newer snapc.
 857                 * They are not writeable until we write all dirty pages
 858                 * associated with 'snapc' get written */
 859                if (index > 0)
 860                        should_loop = true;
 861                dout(" non-head snapc, range whole\n");
 862        }
 863
 864        ceph_put_snap_context(last_snapc);
 865        last_snapc = snapc;
 866
 867        while (!done && index <= end) {
 868                int num_ops = 0, op_idx;
 869                unsigned i, pvec_pages, max_pages, locked_pages = 0;
 870                struct page **pages = NULL, **data_pages;
 871                mempool_t *pool = NULL; /* Becomes non-null if mempool used */
 872                struct page *page;
 873                pgoff_t strip_unit_end = 0;
 874                u64 offset = 0, len = 0;
 875
 876                max_pages = wsize >> PAGE_SHIFT;
 877
 878get_more_pages:
 879                pvec_pages = pagevec_lookup_range_nr_tag(&pvec, mapping, &index,
 880                                                end, PAGECACHE_TAG_DIRTY,
 881                                                max_pages - locked_pages);
 882                dout("pagevec_lookup_range_tag got %d\n", pvec_pages);
 883                if (!pvec_pages && !locked_pages)
 884                        break;
 885                for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
 886                        page = pvec.pages[i];
 887                        dout("? %p idx %lu\n", page, page->index);
 888                        if (locked_pages == 0)
 889                                lock_page(page);  /* first page */
 890                        else if (!trylock_page(page))
 891                                break;
 892
 893                        /* only dirty pages, or our accounting breaks */
 894                        if (unlikely(!PageDirty(page)) ||
 895                            unlikely(page->mapping != mapping)) {
 896                                dout("!dirty or !mapping %p\n", page);
 897                                unlock_page(page);
 898                                continue;
 899                        }
 900                        /* only if matching snap context */
 901                        pgsnapc = page_snap_context(page);
 902                        if (pgsnapc != snapc) {
 903                                dout("page snapc %p %lld != oldest %p %lld\n",
 904                                     pgsnapc, pgsnapc->seq, snapc, snapc->seq);
 905                                if (!should_loop &&
 906                                    !ceph_wbc.head_snapc &&
 907                                    wbc->sync_mode != WB_SYNC_NONE)
 908                                        should_loop = true;
 909                                unlock_page(page);
 910                                continue;
 911                        }
 912                        if (page_offset(page) >= ceph_wbc.i_size) {
 913                                dout("%p page eof %llu\n",
 914                                     page, ceph_wbc.i_size);
 915                                if (ceph_wbc.size_stable ||
 916                                    page_offset(page) >= i_size_read(inode))
 917                                        mapping->a_ops->invalidatepage(page,
 918                                                                0, PAGE_SIZE);
 919                                unlock_page(page);
 920                                continue;
 921                        }
 922                        if (strip_unit_end && (page->index > strip_unit_end)) {
 923                                dout("end of strip unit %p\n", page);
 924                                unlock_page(page);
 925                                break;
 926                        }
 927                        if (PageWriteback(page)) {
 928                                if (wbc->sync_mode == WB_SYNC_NONE) {
 929                                        dout("%p under writeback\n", page);
 930                                        unlock_page(page);
 931                                        continue;
 932                                }
 933                                dout("waiting on writeback %p\n", page);
 934                                wait_on_page_writeback(page);
 935                        }
 936
 937                        if (!clear_page_dirty_for_io(page)) {
 938                                dout("%p !clear_page_dirty_for_io\n", page);
 939                                unlock_page(page);
 940                                continue;
 941                        }
 942
 943                        /*
 944                         * We have something to write.  If this is
 945                         * the first locked page this time through,
 946                         * calculate max possinle write size and
 947                         * allocate a page array
 948                         */
 949                        if (locked_pages == 0) {
 950                                u64 objnum;
 951                                u64 objoff;
 952                                u32 xlen;
 953
 954                                /* prepare async write request */
 955                                offset = (u64)page_offset(page);
 956                                ceph_calc_file_object_mapping(&ci->i_layout,
 957                                                              offset, wsize,
 958                                                              &objnum, &objoff,
 959                                                              &xlen);
 960                                len = xlen;
 961
 962                                num_ops = 1;
 963                                strip_unit_end = page->index +
 964                                        ((len - 1) >> PAGE_SHIFT);
 965
 966                                BUG_ON(pages);
 967                                max_pages = calc_pages_for(0, (u64)len);
 968                                pages = kmalloc_array(max_pages,
 969                                                      sizeof(*pages),
 970                                                      GFP_NOFS);
 971                                if (!pages) {
 972                                        pool = fsc->wb_pagevec_pool;
 973                                        pages = mempool_alloc(pool, GFP_NOFS);
 974                                        BUG_ON(!pages);
 975                                }
 976
 977                                len = 0;
 978                        } else if (page->index !=
 979                                   (offset + len) >> PAGE_SHIFT) {
 980                                if (num_ops >= (pool ?  CEPH_OSD_SLAB_OPS :
 981                                                        CEPH_OSD_MAX_OPS)) {
 982                                        redirty_page_for_writepage(wbc, page);
 983                                        unlock_page(page);
 984                                        break;
 985                                }
 986
 987                                num_ops++;
 988                                offset = (u64)page_offset(page);
 989                                len = 0;
 990                        }
 991
 992                        /* note position of first page in pvec */
 993                        dout("%p will write page %p idx %lu\n",
 994                             inode, page, page->index);
 995
 996                        if (atomic_long_inc_return(&fsc->writeback_count) >
 997                            CONGESTION_ON_THRESH(
 998                                    fsc->mount_options->congestion_kb)) {
 999                                set_bdi_congested(inode_to_bdi(inode),
1000                                                  BLK_RW_ASYNC);
1001                        }
1002
1003
1004                        pages[locked_pages++] = page;
1005                        pvec.pages[i] = NULL;
1006
1007                        len += PAGE_SIZE;
1008                }
1009
1010                /* did we get anything? */
1011                if (!locked_pages)
1012                        goto release_pvec_pages;
1013                if (i) {
1014                        unsigned j, n = 0;
1015                        /* shift unused page to beginning of pvec */
1016                        for (j = 0; j < pvec_pages; j++) {
1017                                if (!pvec.pages[j])
1018                                        continue;
1019                                if (n < j)
1020                                        pvec.pages[n] = pvec.pages[j];
1021                                n++;
1022                        }
1023                        pvec.nr = n;
1024
1025                        if (pvec_pages && i == pvec_pages &&
1026                            locked_pages < max_pages) {
1027                                dout("reached end pvec, trying for more\n");
1028                                pagevec_release(&pvec);
1029                                goto get_more_pages;
1030                        }
1031                }
1032
1033new_request:
1034                offset = page_offset(pages[0]);
1035                len = wsize;
1036
1037                req = ceph_osdc_new_request(&fsc->client->osdc,
1038                                        &ci->i_layout, vino,
1039                                        offset, &len, 0, num_ops,
1040                                        CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1041                                        snapc, ceph_wbc.truncate_seq,
1042                                        ceph_wbc.truncate_size, false);
1043                if (IS_ERR(req)) {
1044                        req = ceph_osdc_new_request(&fsc->client->osdc,
1045                                                &ci->i_layout, vino,
1046                                                offset, &len, 0,
1047                                                min(num_ops,
1048                                                    CEPH_OSD_SLAB_OPS),
1049                                                CEPH_OSD_OP_WRITE,
1050                                                CEPH_OSD_FLAG_WRITE,
1051                                                snapc, ceph_wbc.truncate_seq,
1052                                                ceph_wbc.truncate_size, true);
1053                        BUG_ON(IS_ERR(req));
1054                }
1055                BUG_ON(len < page_offset(pages[locked_pages - 1]) +
1056                             PAGE_SIZE - offset);
1057
1058                req->r_callback = writepages_finish;
1059                req->r_inode = inode;
1060
1061                /* Format the osd request message and submit the write */
1062                len = 0;
1063                data_pages = pages;
1064                op_idx = 0;
1065                for (i = 0; i < locked_pages; i++) {
1066                        u64 cur_offset = page_offset(pages[i]);
1067                        if (offset + len != cur_offset) {
1068                                if (op_idx + 1 == req->r_num_ops)
1069                                        break;
1070                                osd_req_op_extent_dup_last(req, op_idx,
1071                                                           cur_offset - offset);
1072                                dout("writepages got pages at %llu~%llu\n",
1073                                     offset, len);
1074                                osd_req_op_extent_osd_data_pages(req, op_idx,
1075                                                        data_pages, len, 0,
1076                                                        !!pool, false);
1077                                osd_req_op_extent_update(req, op_idx, len);
1078
1079                                len = 0;
1080                                offset = cur_offset; 
1081                                data_pages = pages + i;
1082                                op_idx++;
1083                        }
1084
1085                        set_page_writeback(pages[i]);
1086                        len += PAGE_SIZE;
1087                }
1088
1089                if (ceph_wbc.size_stable) {
1090                        len = min(len, ceph_wbc.i_size - offset);
1091                } else if (i == locked_pages) {
1092                        /* writepages_finish() clears writeback pages
1093                         * according to the data length, so make sure
1094                         * data length covers all locked pages */
1095                        u64 min_len = len + 1 - PAGE_SIZE;
1096                        len = get_writepages_data_length(inode, pages[i - 1],
1097                                                         offset);
1098                        len = max(len, min_len);
1099                }
1100                dout("writepages got pages at %llu~%llu\n", offset, len);
1101
1102                osd_req_op_extent_osd_data_pages(req, op_idx, data_pages, len,
1103                                                 0, !!pool, false);
1104                osd_req_op_extent_update(req, op_idx, len);
1105
1106                BUG_ON(op_idx + 1 != req->r_num_ops);
1107
1108                pool = NULL;
1109                if (i < locked_pages) {
1110                        BUG_ON(num_ops <= req->r_num_ops);
1111                        num_ops -= req->r_num_ops;
1112                        locked_pages -= i;
1113
1114                        /* allocate new pages array for next request */
1115                        data_pages = pages;
1116                        pages = kmalloc_array(locked_pages, sizeof(*pages),
1117                                              GFP_NOFS);
1118                        if (!pages) {
1119                                pool = fsc->wb_pagevec_pool;
1120                                pages = mempool_alloc(pool, GFP_NOFS);
1121                                BUG_ON(!pages);
1122                        }
1123                        memcpy(pages, data_pages + i,
1124                               locked_pages * sizeof(*pages));
1125                        memset(data_pages + i, 0,
1126                               locked_pages * sizeof(*pages));
1127                } else {
1128                        BUG_ON(num_ops != req->r_num_ops);
1129                        index = pages[i - 1]->index + 1;
1130                        /* request message now owns the pages array */
1131                        pages = NULL;
1132                }
1133
1134                req->r_mtime = inode->i_mtime;
1135                rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
1136                BUG_ON(rc);
1137                req = NULL;
1138
1139                wbc->nr_to_write -= i;
1140                if (pages)
1141                        goto new_request;
1142
1143                /*
1144                 * We stop writing back only if we are not doing
1145                 * integrity sync. In case of integrity sync we have to
1146                 * keep going until we have written all the pages
1147                 * we tagged for writeback prior to entering this loop.
1148                 */
1149                if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE)
1150                        done = true;
1151
1152release_pvec_pages:
1153                dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
1154                     pvec.nr ? pvec.pages[0] : NULL);
1155                pagevec_release(&pvec);
1156        }
1157
1158        if (should_loop && !done) {
1159                /* more to do; loop back to beginning of file */
1160                dout("writepages looping back to beginning of file\n");
1161                end = start_index - 1; /* OK even when start_index == 0 */
1162
1163                /* to write dirty pages associated with next snapc,
1164                 * we need to wait until current writes complete */
1165                if (wbc->sync_mode != WB_SYNC_NONE &&
1166                    start_index == 0 && /* all dirty pages were checked */
1167                    !ceph_wbc.head_snapc) {
1168                        struct page *page;
1169                        unsigned i, nr;
1170                        index = 0;
1171                        while ((index <= end) &&
1172                               (nr = pagevec_lookup_tag(&pvec, mapping, &index,
1173                                                PAGECACHE_TAG_WRITEBACK))) {
1174                                for (i = 0; i < nr; i++) {
1175                                        page = pvec.pages[i];
1176                                        if (page_snap_context(page) != snapc)
1177                                                continue;
1178                                        wait_on_page_writeback(page);
1179                                }
1180                                pagevec_release(&pvec);
1181                                cond_resched();
1182                        }
1183                }
1184
1185                start_index = 0;
1186                index = 0;
1187                goto retry;
1188        }
1189
1190        if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1191                mapping->writeback_index = index;
1192
1193out:
1194        ceph_osdc_put_request(req);
1195        ceph_put_snap_context(last_snapc);
1196        dout("writepages dend - startone, rc = %d\n", rc);
1197        return rc;
1198}
1199
1200
1201
1202/*
1203 * See if a given @snapc is either writeable, or already written.
1204 */
1205static int context_is_writeable_or_written(struct inode *inode,
1206                                           struct ceph_snap_context *snapc)
1207{
1208        struct ceph_snap_context *oldest = get_oldest_context(inode, NULL, NULL);
1209        int ret = !oldest || snapc->seq <= oldest->seq;
1210
1211        ceph_put_snap_context(oldest);
1212        return ret;
1213}
1214
1215/*
1216 * We are only allowed to write into/dirty the page if the page is
1217 * clean, or already dirty within the same snap context.
1218 *
1219 * called with page locked.
1220 * return success with page locked,
1221 * or any failure (incl -EAGAIN) with page unlocked.
1222 */
1223static int ceph_update_writeable_page(struct file *file,
1224                            loff_t pos, unsigned len,
1225                            struct page *page)
1226{
1227        struct inode *inode = file_inode(file);
1228        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1229        struct ceph_inode_info *ci = ceph_inode(inode);
1230        loff_t page_off = pos & PAGE_MASK;
1231        int pos_in_page = pos & ~PAGE_MASK;
1232        int end_in_page = pos_in_page + len;
1233        loff_t i_size;
1234        int r;
1235        struct ceph_snap_context *snapc, *oldest;
1236
1237        if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1238                dout(" page %p forced umount\n", page);
1239                unlock_page(page);
1240                return -EIO;
1241        }
1242
1243retry_locked:
1244        /* writepages currently holds page lock, but if we change that later, */
1245        wait_on_page_writeback(page);
1246
1247        snapc = page_snap_context(page);
1248        if (snapc && snapc != ci->i_head_snapc) {
1249                /*
1250                 * this page is already dirty in another (older) snap
1251                 * context!  is it writeable now?
1252                 */
1253                oldest = get_oldest_context(inode, NULL, NULL);
1254                if (snapc->seq > oldest->seq) {
1255                        ceph_put_snap_context(oldest);
1256                        dout(" page %p snapc %p not current or oldest\n",
1257                             page, snapc);
1258                        /*
1259                         * queue for writeback, and wait for snapc to
1260                         * be writeable or written
1261                         */
1262                        snapc = ceph_get_snap_context(snapc);
1263                        unlock_page(page);
1264                        ceph_queue_writeback(inode);
1265                        r = wait_event_killable(ci->i_cap_wq,
1266                               context_is_writeable_or_written(inode, snapc));
1267                        ceph_put_snap_context(snapc);
1268                        if (r == -ERESTARTSYS)
1269                                return r;
1270                        return -EAGAIN;
1271                }
1272                ceph_put_snap_context(oldest);
1273
1274                /* yay, writeable, do it now (without dropping page lock) */
1275                dout(" page %p snapc %p not current, but oldest\n",
1276                     page, snapc);
1277                if (!clear_page_dirty_for_io(page))
1278                        goto retry_locked;
1279                r = writepage_nounlock(page, NULL);
1280                if (r < 0)
1281                        goto fail_unlock;
1282                goto retry_locked;
1283        }
1284
1285        if (PageUptodate(page)) {
1286                dout(" page %p already uptodate\n", page);
1287                return 0;
1288        }
1289
1290        /* full page? */
1291        if (pos_in_page == 0 && len == PAGE_SIZE)
1292                return 0;
1293
1294        /* past end of file? */
1295        i_size = i_size_read(inode);
1296
1297        if (page_off >= i_size ||
1298            (pos_in_page == 0 && (pos+len) >= i_size &&
1299             end_in_page - pos_in_page != PAGE_SIZE)) {
1300                dout(" zeroing %p 0 - %d and %d - %d\n",
1301                     page, pos_in_page, end_in_page, (int)PAGE_SIZE);
1302                zero_user_segments(page,
1303                                   0, pos_in_page,
1304                                   end_in_page, PAGE_SIZE);
1305                return 0;
1306        }
1307
1308        /* we need to read it. */
1309        r = ceph_do_readpage(file, page);
1310        if (r < 0) {
1311                if (r == -EINPROGRESS)
1312                        return -EAGAIN;
1313                goto fail_unlock;
1314        }
1315        goto retry_locked;
1316fail_unlock:
1317        unlock_page(page);
1318        return r;
1319}
1320
1321/*
1322 * We are only allowed to write into/dirty the page if the page is
1323 * clean, or already dirty within the same snap context.
1324 */
1325static int ceph_write_begin(struct file *file, struct address_space *mapping,
1326                            loff_t pos, unsigned len, unsigned flags,
1327                            struct page **pagep, void **fsdata)
1328{
1329        struct inode *inode = file_inode(file);
1330        struct page *page;
1331        pgoff_t index = pos >> PAGE_SHIFT;
1332        int r;
1333
1334        do {
1335                /* get a page */
1336                page = grab_cache_page_write_begin(mapping, index, 0);
1337                if (!page)
1338                        return -ENOMEM;
1339
1340                dout("write_begin file %p inode %p page %p %d~%d\n", file,
1341                     inode, page, (int)pos, (int)len);
1342
1343                r = ceph_update_writeable_page(file, pos, len, page);
1344                if (r < 0)
1345                        put_page(page);
1346                else
1347                        *pagep = page;
1348        } while (r == -EAGAIN);
1349
1350        return r;
1351}
1352
1353/*
1354 * we don't do anything in here that simple_write_end doesn't do
1355 * except adjust dirty page accounting
1356 */
1357static int ceph_write_end(struct file *file, struct address_space *mapping,
1358                          loff_t pos, unsigned len, unsigned copied,
1359                          struct page *page, void *fsdata)
1360{
1361        struct inode *inode = file_inode(file);
1362        bool check_cap = false;
1363
1364        dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1365             inode, page, (int)pos, (int)copied, (int)len);
1366
1367        /* zero the stale part of the page if we did a short copy */
1368        if (!PageUptodate(page)) {
1369                if (copied < len) {
1370                        copied = 0;
1371                        goto out;
1372                }
1373                SetPageUptodate(page);
1374        }
1375
1376        /* did file size increase? */
1377        if (pos+copied > i_size_read(inode))
1378                check_cap = ceph_inode_set_size(inode, pos+copied);
1379
1380        set_page_dirty(page);
1381
1382out:
1383        unlock_page(page);
1384        put_page(page);
1385
1386        if (check_cap)
1387                ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1388
1389        return copied;
1390}
1391
1392/*
1393 * we set .direct_IO to indicate direct io is supported, but since we
1394 * intercept O_DIRECT reads and writes early, this function should
1395 * never get called.
1396 */
1397static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
1398{
1399        WARN_ON(1);
1400        return -EINVAL;
1401}
1402
1403const struct address_space_operations ceph_aops = {
1404        .readpage = ceph_readpage,
1405        .readpages = ceph_readpages,
1406        .writepage = ceph_writepage,
1407        .writepages = ceph_writepages_start,
1408        .write_begin = ceph_write_begin,
1409        .write_end = ceph_write_end,
1410        .set_page_dirty = ceph_set_page_dirty,
1411        .invalidatepage = ceph_invalidatepage,
1412        .releasepage = ceph_releasepage,
1413        .direct_IO = ceph_direct_io,
1414};
1415
1416static void ceph_block_sigs(sigset_t *oldset)
1417{
1418        sigset_t mask;
1419        siginitsetinv(&mask, sigmask(SIGKILL));
1420        sigprocmask(SIG_BLOCK, &mask, oldset);
1421}
1422
1423static void ceph_restore_sigs(sigset_t *oldset)
1424{
1425        sigprocmask(SIG_SETMASK, oldset, NULL);
1426}
1427
1428/*
1429 * vm ops
1430 */
1431static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
1432{
1433        struct vm_area_struct *vma = vmf->vma;
1434        struct inode *inode = file_inode(vma->vm_file);
1435        struct ceph_inode_info *ci = ceph_inode(inode);
1436        struct ceph_file_info *fi = vma->vm_file->private_data;
1437        struct page *pinned_page = NULL;
1438        loff_t off = vmf->pgoff << PAGE_SHIFT;
1439        int want, got, err;
1440        sigset_t oldset;
1441        vm_fault_t ret = VM_FAULT_SIGBUS;
1442
1443        ceph_block_sigs(&oldset);
1444
1445        dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1446             inode, ceph_vinop(inode), off, (size_t)PAGE_SIZE);
1447        if (fi->fmode & CEPH_FILE_MODE_LAZY)
1448                want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1449        else
1450                want = CEPH_CAP_FILE_CACHE;
1451
1452        got = 0;
1453        err = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, -1, &got, &pinned_page);
1454        if (err < 0)
1455                goto out_restore;
1456
1457        dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1458             inode, off, (size_t)PAGE_SIZE, ceph_cap_string(got));
1459
1460        if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1461            ci->i_inline_version == CEPH_INLINE_NONE) {
1462                CEPH_DEFINE_RW_CONTEXT(rw_ctx, got);
1463                ceph_add_rw_context(fi, &rw_ctx);
1464                ret = filemap_fault(vmf);
1465                ceph_del_rw_context(fi, &rw_ctx);
1466                dout("filemap_fault %p %llu~%zd drop cap refs %s ret %x\n",
1467                        inode, off, (size_t)PAGE_SIZE,
1468                                ceph_cap_string(got), ret);
1469        } else
1470                err = -EAGAIN;
1471
1472        if (pinned_page)
1473                put_page(pinned_page);
1474        ceph_put_cap_refs(ci, got);
1475
1476        if (err != -EAGAIN)
1477                goto out_restore;
1478
1479        /* read inline data */
1480        if (off >= PAGE_SIZE) {
1481                /* does not support inline data > PAGE_SIZE */
1482                ret = VM_FAULT_SIGBUS;
1483        } else {
1484                struct address_space *mapping = inode->i_mapping;
1485                struct page *page = find_or_create_page(mapping, 0,
1486                                                mapping_gfp_constraint(mapping,
1487                                                ~__GFP_FS));
1488                if (!page) {
1489                        ret = VM_FAULT_OOM;
1490                        goto out_inline;
1491                }
1492                err = __ceph_do_getattr(inode, page,
1493                                         CEPH_STAT_CAP_INLINE_DATA, true);
1494                if (err < 0 || off >= i_size_read(inode)) {
1495                        unlock_page(page);
1496                        put_page(page);
1497                        ret = vmf_error(err);
1498                        goto out_inline;
1499                }
1500                if (err < PAGE_SIZE)
1501                        zero_user_segment(page, err, PAGE_SIZE);
1502                else
1503                        flush_dcache_page(page);
1504                SetPageUptodate(page);
1505                vmf->page = page;
1506                ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1507out_inline:
1508                dout("filemap_fault %p %llu~%zd read inline data ret %x\n",
1509                     inode, off, (size_t)PAGE_SIZE, ret);
1510        }
1511out_restore:
1512        ceph_restore_sigs(&oldset);
1513        if (err < 0)
1514                ret = vmf_error(err);
1515
1516        return ret;
1517}
1518
1519/*
1520 * Reuse write_begin here for simplicity.
1521 */
1522static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
1523{
1524        struct vm_area_struct *vma = vmf->vma;
1525        struct inode *inode = file_inode(vma->vm_file);
1526        struct ceph_inode_info *ci = ceph_inode(inode);
1527        struct ceph_file_info *fi = vma->vm_file->private_data;
1528        struct ceph_cap_flush *prealloc_cf;
1529        struct page *page = vmf->page;
1530        loff_t off = page_offset(page);
1531        loff_t size = i_size_read(inode);
1532        size_t len;
1533        int want, got, err;
1534        sigset_t oldset;
1535        vm_fault_t ret = VM_FAULT_SIGBUS;
1536
1537        prealloc_cf = ceph_alloc_cap_flush();
1538        if (!prealloc_cf)
1539                return VM_FAULT_OOM;
1540
1541        ceph_block_sigs(&oldset);
1542
1543        if (ci->i_inline_version != CEPH_INLINE_NONE) {
1544                struct page *locked_page = NULL;
1545                if (off == 0) {
1546                        lock_page(page);
1547                        locked_page = page;
1548                }
1549                err = ceph_uninline_data(vma->vm_file, locked_page);
1550                if (locked_page)
1551                        unlock_page(locked_page);
1552                if (err < 0)
1553                        goto out_free;
1554        }
1555
1556        if (off + PAGE_SIZE <= size)
1557                len = PAGE_SIZE;
1558        else
1559                len = size & ~PAGE_MASK;
1560
1561        dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1562             inode, ceph_vinop(inode), off, len, size);
1563        if (fi->fmode & CEPH_FILE_MODE_LAZY)
1564                want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1565        else
1566                want = CEPH_CAP_FILE_BUFFER;
1567
1568        got = 0;
1569        err = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
1570                            &got, NULL);
1571        if (err < 0)
1572                goto out_free;
1573
1574        dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1575             inode, off, len, ceph_cap_string(got));
1576
1577        /* Update time before taking page lock */
1578        file_update_time(vma->vm_file);
1579
1580        do {
1581                lock_page(page);
1582
1583                if ((off > size) || (page->mapping != inode->i_mapping)) {
1584                        unlock_page(page);
1585                        ret = VM_FAULT_NOPAGE;
1586                        break;
1587                }
1588
1589                err = ceph_update_writeable_page(vma->vm_file, off, len, page);
1590                if (err >= 0) {
1591                        /* success.  we'll keep the page locked. */
1592                        set_page_dirty(page);
1593                        ret = VM_FAULT_LOCKED;
1594                }
1595        } while (err == -EAGAIN);
1596
1597        if (ret == VM_FAULT_LOCKED ||
1598            ci->i_inline_version != CEPH_INLINE_NONE) {
1599                int dirty;
1600                spin_lock(&ci->i_ceph_lock);
1601                ci->i_inline_version = CEPH_INLINE_NONE;
1602                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1603                                               &prealloc_cf);
1604                spin_unlock(&ci->i_ceph_lock);
1605                if (dirty)
1606                        __mark_inode_dirty(inode, dirty);
1607        }
1608
1609        dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %x\n",
1610             inode, off, len, ceph_cap_string(got), ret);
1611        ceph_put_cap_refs(ci, got);
1612out_free:
1613        ceph_restore_sigs(&oldset);
1614        ceph_free_cap_flush(prealloc_cf);
1615        if (err < 0)
1616                ret = vmf_error(err);
1617        return ret;
1618}
1619
1620void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1621                           char *data, size_t len)
1622{
1623        struct address_space *mapping = inode->i_mapping;
1624        struct page *page;
1625
1626        if (locked_page) {
1627                page = locked_page;
1628        } else {
1629                if (i_size_read(inode) == 0)
1630                        return;
1631                page = find_or_create_page(mapping, 0,
1632                                           mapping_gfp_constraint(mapping,
1633                                           ~__GFP_FS));
1634                if (!page)
1635                        return;
1636                if (PageUptodate(page)) {
1637                        unlock_page(page);
1638                        put_page(page);
1639                        return;
1640                }
1641        }
1642
1643        dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1644             inode, ceph_vinop(inode), len, locked_page);
1645
1646        if (len > 0) {
1647                void *kaddr = kmap_atomic(page);
1648                memcpy(kaddr, data, len);
1649                kunmap_atomic(kaddr);
1650        }
1651
1652        if (page != locked_page) {
1653                if (len < PAGE_SIZE)
1654                        zero_user_segment(page, len, PAGE_SIZE);
1655                else
1656                        flush_dcache_page(page);
1657
1658                SetPageUptodate(page);
1659                unlock_page(page);
1660                put_page(page);
1661        }
1662}
1663
1664int ceph_uninline_data(struct file *filp, struct page *locked_page)
1665{
1666        struct inode *inode = file_inode(filp);
1667        struct ceph_inode_info *ci = ceph_inode(inode);
1668        struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1669        struct ceph_osd_request *req;
1670        struct page *page = NULL;
1671        u64 len, inline_version;
1672        int err = 0;
1673        bool from_pagecache = false;
1674
1675        spin_lock(&ci->i_ceph_lock);
1676        inline_version = ci->i_inline_version;
1677        spin_unlock(&ci->i_ceph_lock);
1678
1679        dout("uninline_data %p %llx.%llx inline_version %llu\n",
1680             inode, ceph_vinop(inode), inline_version);
1681
1682        if (inline_version == 1 || /* initial version, no data */
1683            inline_version == CEPH_INLINE_NONE)
1684                goto out;
1685
1686        if (locked_page) {
1687                page = locked_page;
1688                WARN_ON(!PageUptodate(page));
1689        } else if (ceph_caps_issued(ci) &
1690                   (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1691                page = find_get_page(inode->i_mapping, 0);
1692                if (page) {
1693                        if (PageUptodate(page)) {
1694                                from_pagecache = true;
1695                                lock_page(page);
1696                        } else {
1697                                put_page(page);
1698                                page = NULL;
1699                        }
1700                }
1701        }
1702
1703        if (page) {
1704                len = i_size_read(inode);
1705                if (len > PAGE_SIZE)
1706                        len = PAGE_SIZE;
1707        } else {
1708                page = __page_cache_alloc(GFP_NOFS);
1709                if (!page) {
1710                        err = -ENOMEM;
1711                        goto out;
1712                }
1713                err = __ceph_do_getattr(inode, page,
1714                                        CEPH_STAT_CAP_INLINE_DATA, true);
1715                if (err < 0) {
1716                        /* no inline data */
1717                        if (err == -ENODATA)
1718                                err = 0;
1719                        goto out;
1720                }
1721                len = err;
1722        }
1723
1724        req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1725                                    ceph_vino(inode), 0, &len, 0, 1,
1726                                    CEPH_OSD_OP_CREATE, CEPH_OSD_FLAG_WRITE,
1727                                    NULL, 0, 0, false);
1728        if (IS_ERR(req)) {
1729                err = PTR_ERR(req);
1730                goto out;
1731        }
1732
1733        req->r_mtime = inode->i_mtime;
1734        err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1735        if (!err)
1736                err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1737        ceph_osdc_put_request(req);
1738        if (err < 0)
1739                goto out;
1740
1741        req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1742                                    ceph_vino(inode), 0, &len, 1, 3,
1743                                    CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1744                                    NULL, ci->i_truncate_seq,
1745                                    ci->i_truncate_size, false);
1746        if (IS_ERR(req)) {
1747                err = PTR_ERR(req);
1748                goto out;
1749        }
1750
1751        osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1752
1753        {
1754                __le64 xattr_buf = cpu_to_le64(inline_version);
1755                err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1756                                            "inline_version", &xattr_buf,
1757                                            sizeof(xattr_buf),
1758                                            CEPH_OSD_CMPXATTR_OP_GT,
1759                                            CEPH_OSD_CMPXATTR_MODE_U64);
1760                if (err)
1761                        goto out_put;
1762        }
1763
1764        {
1765                char xattr_buf[32];
1766                int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1767                                         "%llu", inline_version);
1768                err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1769                                            "inline_version",
1770                                            xattr_buf, xattr_len, 0, 0);
1771                if (err)
1772                        goto out_put;
1773        }
1774
1775        req->r_mtime = inode->i_mtime;
1776        err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1777        if (!err)
1778                err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1779out_put:
1780        ceph_osdc_put_request(req);
1781        if (err == -ECANCELED)
1782                err = 0;
1783out:
1784        if (page && page != locked_page) {
1785                if (from_pagecache) {
1786                        unlock_page(page);
1787                        put_page(page);
1788                } else
1789                        __free_pages(page, 0);
1790        }
1791
1792        dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1793             inode, ceph_vinop(inode), inline_version, err);
1794        return err;
1795}
1796
1797static const struct vm_operations_struct ceph_vmops = {
1798        .fault          = ceph_filemap_fault,
1799        .page_mkwrite   = ceph_page_mkwrite,
1800};
1801
1802int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1803{
1804        struct address_space *mapping = file->f_mapping;
1805
1806        if (!mapping->a_ops->readpage)
1807                return -ENOEXEC;
1808        file_accessed(file);
1809        vma->vm_ops = &ceph_vmops;
1810        return 0;
1811}
1812
1813enum {
1814        POOL_READ       = 1,
1815        POOL_WRITE      = 2,
1816};
1817
1818static int __ceph_pool_perm_get(struct ceph_inode_info *ci,
1819                                s64 pool, struct ceph_string *pool_ns)
1820{
1821        struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1822        struct ceph_mds_client *mdsc = fsc->mdsc;
1823        struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1824        struct rb_node **p, *parent;
1825        struct ceph_pool_perm *perm;
1826        struct page **pages;
1827        size_t pool_ns_len;
1828        int err = 0, err2 = 0, have = 0;
1829
1830        down_read(&mdsc->pool_perm_rwsem);
1831        p = &mdsc->pool_perm_tree.rb_node;
1832        while (*p) {
1833                perm = rb_entry(*p, struct ceph_pool_perm, node);
1834                if (pool < perm->pool)
1835                        p = &(*p)->rb_left;
1836                else if (pool > perm->pool)
1837                        p = &(*p)->rb_right;
1838                else {
1839                        int ret = ceph_compare_string(pool_ns,
1840                                                perm->pool_ns,
1841                                                perm->pool_ns_len);
1842                        if (ret < 0)
1843                                p = &(*p)->rb_left;
1844                        else if (ret > 0)
1845                                p = &(*p)->rb_right;
1846                        else {
1847                                have = perm->perm;
1848                                break;
1849                        }
1850                }
1851        }
1852        up_read(&mdsc->pool_perm_rwsem);
1853        if (*p)
1854                goto out;
1855
1856        if (pool_ns)
1857                dout("__ceph_pool_perm_get pool %lld ns %.*s no perm cached\n",
1858                     pool, (int)pool_ns->len, pool_ns->str);
1859        else
1860                dout("__ceph_pool_perm_get pool %lld no perm cached\n", pool);
1861
1862        down_write(&mdsc->pool_perm_rwsem);
1863        p = &mdsc->pool_perm_tree.rb_node;
1864        parent = NULL;
1865        while (*p) {
1866                parent = *p;
1867                perm = rb_entry(parent, struct ceph_pool_perm, node);
1868                if (pool < perm->pool)
1869                        p = &(*p)->rb_left;
1870                else if (pool > perm->pool)
1871                        p = &(*p)->rb_right;
1872                else {
1873                        int ret = ceph_compare_string(pool_ns,
1874                                                perm->pool_ns,
1875                                                perm->pool_ns_len);
1876                        if (ret < 0)
1877                                p = &(*p)->rb_left;
1878                        else if (ret > 0)
1879                                p = &(*p)->rb_right;
1880                        else {
1881                                have = perm->perm;
1882                                break;
1883                        }
1884                }
1885        }
1886        if (*p) {
1887                up_write(&mdsc->pool_perm_rwsem);
1888                goto out;
1889        }
1890
1891        rd_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1892                                         1, false, GFP_NOFS);
1893        if (!rd_req) {
1894                err = -ENOMEM;
1895                goto out_unlock;
1896        }
1897
1898        rd_req->r_flags = CEPH_OSD_FLAG_READ;
1899        osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1900        rd_req->r_base_oloc.pool = pool;
1901        if (pool_ns)
1902                rd_req->r_base_oloc.pool_ns = ceph_get_string(pool_ns);
1903        ceph_oid_printf(&rd_req->r_base_oid, "%llx.00000000", ci->i_vino.ino);
1904
1905        err = ceph_osdc_alloc_messages(rd_req, GFP_NOFS);
1906        if (err)
1907                goto out_unlock;
1908
1909        wr_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1910                                         1, false, GFP_NOFS);
1911        if (!wr_req) {
1912                err = -ENOMEM;
1913                goto out_unlock;
1914        }
1915
1916        wr_req->r_flags = CEPH_OSD_FLAG_WRITE;
1917        osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
1918        ceph_oloc_copy(&wr_req->r_base_oloc, &rd_req->r_base_oloc);
1919        ceph_oid_copy(&wr_req->r_base_oid, &rd_req->r_base_oid);
1920
1921        err = ceph_osdc_alloc_messages(wr_req, GFP_NOFS);
1922        if (err)
1923                goto out_unlock;
1924
1925        /* one page should be large enough for STAT data */
1926        pages = ceph_alloc_page_vector(1, GFP_KERNEL);
1927        if (IS_ERR(pages)) {
1928                err = PTR_ERR(pages);
1929                goto out_unlock;
1930        }
1931
1932        osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
1933                                     0, false, true);
1934        err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
1935
1936        wr_req->r_mtime = ci->vfs_inode.i_mtime;
1937        err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
1938
1939        if (!err)
1940                err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
1941        if (!err2)
1942                err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
1943
1944        if (err >= 0 || err == -ENOENT)
1945                have |= POOL_READ;
1946        else if (err != -EPERM)
1947                goto out_unlock;
1948
1949        if (err2 == 0 || err2 == -EEXIST)
1950                have |= POOL_WRITE;
1951        else if (err2 != -EPERM) {
1952                err = err2;
1953                goto out_unlock;
1954        }
1955
1956        pool_ns_len = pool_ns ? pool_ns->len : 0;
1957        perm = kmalloc(sizeof(*perm) + pool_ns_len + 1, GFP_NOFS);
1958        if (!perm) {
1959                err = -ENOMEM;
1960                goto out_unlock;
1961        }
1962
1963        perm->pool = pool;
1964        perm->perm = have;
1965        perm->pool_ns_len = pool_ns_len;
1966        if (pool_ns_len > 0)
1967                memcpy(perm->pool_ns, pool_ns->str, pool_ns_len);
1968        perm->pool_ns[pool_ns_len] = 0;
1969
1970        rb_link_node(&perm->node, parent, p);
1971        rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
1972        err = 0;
1973out_unlock:
1974        up_write(&mdsc->pool_perm_rwsem);
1975
1976        ceph_osdc_put_request(rd_req);
1977        ceph_osdc_put_request(wr_req);
1978out:
1979        if (!err)
1980                err = have;
1981        if (pool_ns)
1982                dout("__ceph_pool_perm_get pool %lld ns %.*s result = %d\n",
1983                     pool, (int)pool_ns->len, pool_ns->str, err);
1984        else
1985                dout("__ceph_pool_perm_get pool %lld result = %d\n", pool, err);
1986        return err;
1987}
1988
1989int ceph_pool_perm_check(struct ceph_inode_info *ci, int need)
1990{
1991        s64 pool;
1992        struct ceph_string *pool_ns;
1993        int ret, flags;
1994
1995        if (ci->i_vino.snap != CEPH_NOSNAP) {
1996                /*
1997                 * Pool permission check needs to write to the first object.
1998                 * But for snapshot, head of the first object may have alread
1999                 * been deleted. Skip check to avoid creating orphan object.
2000                 */
2001                return 0;
2002        }
2003
2004        if (ceph_test_mount_opt(ceph_inode_to_client(&ci->vfs_inode),
2005                                NOPOOLPERM))
2006                return 0;
2007
2008        spin_lock(&ci->i_ceph_lock);
2009        flags = ci->i_ceph_flags;
2010        pool = ci->i_layout.pool_id;
2011        spin_unlock(&ci->i_ceph_lock);
2012check:
2013        if (flags & CEPH_I_POOL_PERM) {
2014                if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
2015                        dout("ceph_pool_perm_check pool %lld no read perm\n",
2016                             pool);
2017                        return -EPERM;
2018                }
2019                if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
2020                        dout("ceph_pool_perm_check pool %lld no write perm\n",
2021                             pool);
2022                        return -EPERM;
2023                }
2024                return 0;
2025        }
2026
2027        pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
2028        ret = __ceph_pool_perm_get(ci, pool, pool_ns);
2029        ceph_put_string(pool_ns);
2030        if (ret < 0)
2031                return ret;
2032
2033        flags = CEPH_I_POOL_PERM;
2034        if (ret & POOL_READ)
2035                flags |= CEPH_I_POOL_RD;
2036        if (ret & POOL_WRITE)
2037                flags |= CEPH_I_POOL_WR;
2038
2039        spin_lock(&ci->i_ceph_lock);
2040        if (pool == ci->i_layout.pool_id &&
2041            pool_ns == rcu_dereference_raw(ci->i_layout.pool_ns)) {
2042                ci->i_ceph_flags |= flags;
2043        } else {
2044                pool = ci->i_layout.pool_id;
2045                flags = ci->i_ceph_flags;
2046        }
2047        spin_unlock(&ci->i_ceph_lock);
2048        goto check;
2049}
2050
2051void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
2052{
2053        struct ceph_pool_perm *perm;
2054        struct rb_node *n;
2055
2056        while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
2057                n = rb_first(&mdsc->pool_perm_tree);
2058                perm = rb_entry(n, struct ceph_pool_perm, node);
2059                rb_erase(n, &mdsc->pool_perm_tree);
2060                kfree(perm);
2061        }
2062}
2063