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