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
  16#include "super.h"
  17#include "mds_client.h"
  18#include "cache.h"
  19#include "metric.h"
  20#include <linux/ceph/osd_client.h>
  21#include <linux/ceph/striper.h>
  22
  23/*
  24 * Ceph address space ops.
  25 *
  26 * There are a few funny things going on here.
  27 *
  28 * The page->private field is used to reference a struct
  29 * ceph_snap_context for _every_ dirty page.  This indicates which
  30 * snapshot the page was logically dirtied in, and thus which snap
  31 * context needs to be associated with the osd write during writeback.
  32 *
  33 * Similarly, struct ceph_inode_info maintains a set of counters to
  34 * count dirty pages on the inode.  In the absence of snapshots,
  35 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
  36 *
  37 * When a snapshot is taken (that is, when the client receives
  38 * notification that a snapshot was taken), each inode with caps and
  39 * with dirty pages (dirty pages implies there is a cap) gets a new
  40 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
  41 * order, new snaps go to the tail).  The i_wrbuffer_ref_head count is
  42 * moved to capsnap->dirty. (Unless a sync write is currently in
  43 * progress.  In that case, the capsnap is said to be "pending", new
  44 * writes cannot start, and the capsnap isn't "finalized" until the
  45 * write completes (or fails) and a final size/mtime for the inode for
  46 * that snap can be settled upon.)  i_wrbuffer_ref_head is reset to 0.
  47 *
  48 * On writeback, we must submit writes to the osd IN SNAP ORDER.  So,
  49 * we look for the first capsnap in i_cap_snaps and write out pages in
  50 * that snap context _only_.  Then we move on to the next capsnap,
  51 * eventually reaching the "live" or "head" context (i.e., pages that
  52 * are not yet snapped) and are writing the most recently dirtied
  53 * pages.
  54 *
  55 * Invalidate and so forth must take care to ensure the dirty page
  56 * accounting is preserved.
  57 */
  58
  59#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
  60#define CONGESTION_OFF_THRESH(congestion_kb)				\
  61	(CONGESTION_ON_THRESH(congestion_kb) -				\
  62	 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
  63
  64static inline struct ceph_snap_context *page_snap_context(struct page *page)
  65{
  66	if (PagePrivate(page))
  67		return (void *)page->private;
  68	return NULL;
  69}
  70
  71/*
  72 * Dirty a page.  Optimistically adjust accounting, on the assumption
  73 * that we won't race with invalidate.  If we do, readjust.
  74 */
  75static int ceph_set_page_dirty(struct page *page)
  76{
  77	struct address_space *mapping = page->mapping;
  78	struct inode *inode;
  79	struct ceph_inode_info *ci;
  80	struct ceph_snap_context *snapc;
  81	int ret;
  82
  83	if (unlikely(!mapping))
  84		return !TestSetPageDirty(page);
  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	page->private = (unsigned long)snapc;
 128	SetPagePrivate(page);
 129
 130	ret = __set_page_dirty_nobuffers(page);
 131	WARN_ON(!PageLocked(page));
 132	WARN_ON(!page->mapping);
 133
 134	return ret;
 135}
 136
 137/*
 138 * If we are truncating the full page (i.e. offset == 0), adjust the
 139 * dirty page counters appropriately.  Only called if there is private
 140 * data on the page.
 141 */
 142static void ceph_invalidatepage(struct page *page, unsigned int offset,
 143				unsigned int length)
 144{
 145	struct inode *inode;
 146	struct ceph_inode_info *ci;
 147	struct ceph_snap_context *snapc = page_snap_context(page);
 148
 149	inode = page->mapping->host;
 150	ci = ceph_inode(inode);
 151
 152	if (offset != 0 || length != PAGE_SIZE) {
 153		dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
 154		     inode, page, page->index, offset, length);
 155		return;
 156	}
 157
 158	ceph_invalidate_fscache_page(inode, page);
 159
 160	WARN_ON(!PageLocked(page));
 161	if (!PagePrivate(page))
 162		return;
 163
 
 
 
 
 
 
 
 
 
 
 164	dout("%p invalidatepage %p idx %lu full dirty page\n",
 165	     inode, page, page->index);
 166
 167	ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 168	ceph_put_snap_context(snapc);
 169	page->private = 0;
 170	ClearPagePrivate(page);
 171}
 172
 173static int ceph_releasepage(struct page *page, gfp_t g)
 174{
 175	dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
 176	     page, page->index, PageDirty(page) ? "" : "not ");
 
 177
 178	/* Can we release the page from the cache? */
 179	if (!ceph_release_fscache_page(page, g))
 180		return 0;
 181
 182	return !PagePrivate(page);
 183}
 184
 185/*
 186 * Read some contiguous pages.  If we cross a stripe boundary, shorten
 187 * *plen.  Return number of bytes read, or error.
 188 */
 189static int ceph_sync_readpages(struct ceph_fs_client *fsc,
 190			       struct ceph_vino vino,
 191			       struct ceph_file_layout *layout,
 192			       u64 off, u64 *plen,
 193			       u32 truncate_seq, u64 truncate_size,
 194			       struct page **pages, int num_pages,
 195			       int page_align)
 196{
 197	struct ceph_osd_client *osdc = &fsc->client->osdc;
 198	struct ceph_osd_request *req;
 199	int rc = 0;
 200
 201	dout("readpages on ino %llx.%llx on %llu~%llu\n", vino.ino,
 202	     vino.snap, off, *plen);
 203	req = ceph_osdc_new_request(osdc, layout, vino, off, plen, 0, 1,
 204				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
 205				    NULL, truncate_seq, truncate_size,
 206				    false);
 207	if (IS_ERR(req))
 208		return PTR_ERR(req);
 209
 210	/* it may be a short read due to an object boundary */
 211	osd_req_op_extent_osd_data_pages(req, 0,
 212				pages, *plen, page_align, false, false);
 213
 214	dout("readpages  final extent is %llu~%llu (%llu bytes align %d)\n",
 215	     off, *plen, *plen, page_align);
 216
 217	rc = ceph_osdc_start_request(osdc, req, false);
 218	if (!rc)
 219		rc = ceph_osdc_wait_request(osdc, req);
 220
 221	ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
 222				 req->r_end_latency, rc);
 223
 224	ceph_osdc_put_request(req);
 225	dout("readpages result %d\n", rc);
 226	return rc;
 227}
 228
 229/*
 230 * read a single page, without unlocking it.
 231 */
 232static int ceph_do_readpage(struct file *filp, struct page *page)
 233{
 234	struct inode *inode = file_inode(filp);
 235	struct ceph_inode_info *ci = ceph_inode(inode);
 236	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 
 237	int err = 0;
 238	u64 off = page_offset(page);
 239	u64 len = PAGE_SIZE;
 240
 241	if (off >= i_size_read(inode)) {
 242		zero_user_segment(page, 0, PAGE_SIZE);
 243		SetPageUptodate(page);
 244		return 0;
 245	}
 246
 247	if (ci->i_inline_version != CEPH_INLINE_NONE) {
 248		/*
 249		 * Uptodate inline data should have been added
 250		 * into page cache while getting Fcr caps.
 251		 */
 252		if (off == 0)
 253			return -EINVAL;
 254		zero_user_segment(page, 0, PAGE_SIZE);
 255		SetPageUptodate(page);
 256		return 0;
 257	}
 258
 259	err = ceph_readpage_from_fscache(inode, page);
 
 260	if (err == 0)
 261		return -EINPROGRESS;
 262
 263	dout("readpage inode %p file %p page %p index %lu\n",
 264	     inode, filp, page, page->index);
 265	err = ceph_sync_readpages(fsc, ceph_vino(inode),
 266				  &ci->i_layout, off, &len,
 267				  ci->i_truncate_seq, ci->i_truncate_size,
 268				  &page, 1, 0);
 269	if (err == -ENOENT)
 270		err = 0;
 271	if (err < 0) {
 272		SetPageError(page);
 273		ceph_fscache_readpage_cancel(inode, page);
 274		if (err == -EBLACKLISTED)
 275			fsc->blacklisted = true;
 276		goto out;
 277	}
 278	if (err < PAGE_SIZE)
 279		/* zero fill remainder of page */
 280		zero_user_segment(page, err, PAGE_SIZE);
 281	else
 282		flush_dcache_page(page);
 283
 
 284	SetPageUptodate(page);
 285	ceph_readpage_to_fscache(inode, page);
 
 
 286
 287out:
 288	return err < 0 ? err : 0;
 289}
 290
 291static int ceph_readpage(struct file *filp, struct page *page)
 292{
 293	int r = ceph_do_readpage(filp, page);
 294	if (r != -EINPROGRESS)
 295		unlock_page(page);
 296	else
 297		r = 0;
 298	return r;
 299}
 300
 301/*
 302 * Finish an async read(ahead) op.
 303 */
 304static void finish_read(struct ceph_osd_request *req)
 305{
 306	struct inode *inode = req->r_inode;
 307	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 308	struct ceph_osd_data *osd_data;
 309	int rc = req->r_result <= 0 ? req->r_result : 0;
 310	int bytes = req->r_result >= 0 ? req->r_result : 0;
 311	int num_pages;
 312	int i;
 313
 314	dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
 315	if (rc == -EBLACKLISTED)
 316		ceph_inode_to_client(inode)->blacklisted = true;
 317
 318	/* unlock all pages, zeroing any data we didn't read */
 319	osd_data = osd_req_op_extent_osd_data(req, 0);
 320	BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 321	num_pages = calc_pages_for((u64)osd_data->alignment,
 322					(u64)osd_data->length);
 323	for (i = 0; i < num_pages; i++) {
 324		struct page *page = osd_data->pages[i];
 325
 326		if (rc < 0 && rc != -ENOENT) {
 327			ceph_fscache_readpage_cancel(inode, page);
 328			goto unlock;
 329		}
 330		if (bytes < (int)PAGE_SIZE) {
 331			/* zero (remainder of) page */
 332			int s = bytes < 0 ? 0 : bytes;
 333			zero_user_segment(page, s, PAGE_SIZE);
 334		}
 335 		dout("finish_read %p uptodate %p idx %lu\n", inode, page,
 336		     page->index);
 337		flush_dcache_page(page);
 338		SetPageUptodate(page);
 339		ceph_readpage_to_fscache(inode, page);
 340unlock:
 341		unlock_page(page);
 342		put_page(page);
 343		bytes -= PAGE_SIZE;
 344	}
 
 
 345
 346	ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
 347				 req->r_end_latency, rc);
 
 348
 349	kfree(osd_data->pages);
 
 350}
 351
 352/*
 353 * start an async read(ahead) operation.  return nr_pages we submitted
 354 * a read for on success, or negative error code.
 355 */
 356static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 357		      struct list_head *page_list, int max)
 358{
 359	struct ceph_osd_client *osdc =
 360		&ceph_inode_to_client(inode)->client->osdc;
 361	struct ceph_inode_info *ci = ceph_inode(inode);
 362	struct page *page = lru_to_page(page_list);
 363	struct ceph_vino vino;
 364	struct ceph_osd_request *req;
 365	u64 off;
 366	u64 len;
 367	int i;
 368	struct page **pages;
 369	pgoff_t next_index;
 370	int nr_pages = 0;
 371	int got = 0;
 372	int ret = 0;
 373
 374	if (!rw_ctx) {
 375		/* caller of readpages does not hold buffer and read caps
 376		 * (fadvise, madvise and readahead cases) */
 377		int want = CEPH_CAP_FILE_CACHE;
 378		ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want,
 379					true, &got);
 380		if (ret < 0) {
 381			dout("start_read %p, error getting cap\n", inode);
 382		} else if (!(got & want)) {
 383			dout("start_read %p, no cache cap\n", inode);
 384			ret = 0;
 385		}
 386		if (ret <= 0) {
 387			if (got)
 388				ceph_put_cap_refs(ci, got);
 389			while (!list_empty(page_list)) {
 390				page = lru_to_page(page_list);
 391				list_del(&page->lru);
 392				put_page(page);
 393			}
 394			return ret;
 395		}
 396	}
 397
 398	off = (u64) page_offset(page);
 399
 400	/* count pages */
 401	next_index = page->index;
 402	list_for_each_entry_reverse(page, page_list, lru) {
 403		if (page->index != next_index)
 404			break;
 405		nr_pages++;
 406		next_index++;
 407		if (max && nr_pages == max)
 408			break;
 409	}
 410	len = nr_pages << PAGE_SHIFT;
 411	dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
 412	     off, len);
 413	vino = ceph_vino(inode);
 414	req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
 415				    0, 1, CEPH_OSD_OP_READ,
 416				    CEPH_OSD_FLAG_READ, NULL,
 417				    ci->i_truncate_seq, ci->i_truncate_size,
 418				    false);
 419	if (IS_ERR(req)) {
 420		ret = PTR_ERR(req);
 421		goto out;
 422	}
 423
 424	/* build page vector */
 425	nr_pages = calc_pages_for(0, len);
 426	pages = kmalloc_array(nr_pages, sizeof(*pages), GFP_KERNEL);
 427	if (!pages) {
 428		ret = -ENOMEM;
 429		goto out_put;
 430	}
 431	for (i = 0; i < nr_pages; ++i) {
 432		page = list_entry(page_list->prev, struct page, lru);
 433		BUG_ON(PageLocked(page));
 434		list_del(&page->lru);
 435
 436 		dout("start_read %p adding %p idx %lu\n", inode, page,
 437		     page->index);
 438		if (add_to_page_cache_lru(page, &inode->i_data, page->index,
 439					  GFP_KERNEL)) {
 440			ceph_fscache_uncache_page(inode, page);
 441			put_page(page);
 442			dout("start_read %p add_to_page_cache failed %p\n",
 443			     inode, page);
 444			nr_pages = i;
 445			if (nr_pages > 0) {
 446				len = nr_pages << PAGE_SHIFT;
 447				osd_req_op_extent_update(req, 0, len);
 448				break;
 449			}
 450			goto out_pages;
 451		}
 452		pages[i] = page;
 453	}
 454	osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
 455	req->r_callback = finish_read;
 456	req->r_inode = inode;
 457
 
 
 458	dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
 459	ret = ceph_osdc_start_request(osdc, req, false);
 460	if (ret < 0)
 461		goto out_pages;
 462	ceph_osdc_put_request(req);
 463
 464	/* After adding locked pages to page cache, the inode holds cache cap.
 465	 * So we can drop our cap refs. */
 466	if (got)
 467		ceph_put_cap_refs(ci, got);
 468
 469	return nr_pages;
 470
 471out_pages:
 472	for (i = 0; i < nr_pages; ++i) {
 473		ceph_fscache_readpage_cancel(inode, pages[i]);
 474		unlock_page(pages[i]);
 475	}
 476	ceph_put_page_vector(pages, nr_pages, false);
 477out_put:
 478	ceph_osdc_put_request(req);
 479out:
 480	if (got)
 481		ceph_put_cap_refs(ci, got);
 482	return ret;
 483}
 484
 485
 486/*
 487 * Read multiple pages.  Leave pages we don't read + unlock in page_list;
 488 * the caller (VM) cleans them up.
 489 */
 490static int ceph_readpages(struct file *file, struct address_space *mapping,
 491			  struct list_head *page_list, unsigned nr_pages)
 492{
 493	struct inode *inode = file_inode(file);
 494	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 495	struct ceph_file_info *fi = file->private_data;
 496	struct ceph_rw_context *rw_ctx;
 497	int rc = 0;
 498	int max = 0;
 499
 500	if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
 501		return -EINVAL;
 502
 503	rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
 504					 &nr_pages);
 505
 506	if (rc == 0)
 507		goto out;
 508
 509	rw_ctx = ceph_find_rw_context(fi);
 510	max = fsc->mount_options->rsize >> PAGE_SHIFT;
 511	dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
 512	     inode, file, rw_ctx, nr_pages, max);
 
 
 
 513	while (!list_empty(page_list)) {
 514		rc = start_read(inode, rw_ctx, page_list, max);
 515		if (rc < 0)
 516			goto out;
 
 517	}
 518out:
 519	ceph_fscache_readpages_cancel(inode, page_list);
 520
 521	dout("readpages %p file %p ret %d\n", inode, file, rc);
 522	return rc;
 523}
 524
 525struct ceph_writeback_ctl
 526{
 527	loff_t i_size;
 528	u64 truncate_size;
 529	u32 truncate_seq;
 530	bool size_stable;
 531	bool head_snapc;
 532};
 533
 534/*
 535 * Get ref for the oldest snapc for an inode with dirty data... that is, the
 536 * only snap context we are allowed to write back.
 537 */
 538static struct ceph_snap_context *
 539get_oldest_context(struct inode *inode, struct ceph_writeback_ctl *ctl,
 540		   struct ceph_snap_context *page_snapc)
 541{
 542	struct ceph_inode_info *ci = ceph_inode(inode);
 543	struct ceph_snap_context *snapc = NULL;
 544	struct ceph_cap_snap *capsnap = NULL;
 545
 546	spin_lock(&ci->i_ceph_lock);
 547	list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 548		dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
 549		     capsnap->context, capsnap->dirty_pages);
 550		if (!capsnap->dirty_pages)
 551			continue;
 552
 553		/* get i_size, truncate_{seq,size} for page_snapc? */
 554		if (snapc && capsnap->context != page_snapc)
 555			continue;
 556
 557		if (ctl) {
 558			if (capsnap->writing) {
 559				ctl->i_size = i_size_read(inode);
 560				ctl->size_stable = false;
 561			} else {
 562				ctl->i_size = capsnap->size;
 563				ctl->size_stable = true;
 564			}
 565			ctl->truncate_size = capsnap->truncate_size;
 566			ctl->truncate_seq = capsnap->truncate_seq;
 567			ctl->head_snapc = false;
 568		}
 569
 570		if (snapc)
 571			break;
 572
 573		snapc = ceph_get_snap_context(capsnap->context);
 574		if (!page_snapc ||
 575		    page_snapc == snapc ||
 576		    page_snapc->seq > snapc->seq)
 577			break;
 
 578	}
 579	if (!snapc && ci->i_wrbuffer_ref_head) {
 580		snapc = ceph_get_snap_context(ci->i_head_snapc);
 581		dout(" head snapc %p has %d dirty pages\n",
 582		     snapc, ci->i_wrbuffer_ref_head);
 583		if (ctl) {
 584			ctl->i_size = i_size_read(inode);
 585			ctl->truncate_size = ci->i_truncate_size;
 586			ctl->truncate_seq = ci->i_truncate_seq;
 587			ctl->size_stable = false;
 588			ctl->head_snapc = true;
 589		}
 590	}
 591	spin_unlock(&ci->i_ceph_lock);
 592	return snapc;
 593}
 594
 595static u64 get_writepages_data_length(struct inode *inode,
 596				      struct page *page, u64 start)
 597{
 598	struct ceph_inode_info *ci = ceph_inode(inode);
 599	struct ceph_snap_context *snapc = page_snap_context(page);
 600	struct ceph_cap_snap *capsnap = NULL;
 601	u64 end = i_size_read(inode);
 602
 603	if (snapc != ci->i_head_snapc) {
 604		bool found = false;
 605		spin_lock(&ci->i_ceph_lock);
 606		list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
 607			if (capsnap->context == snapc) {
 608				if (!capsnap->writing)
 609					end = capsnap->size;
 610				found = true;
 611				break;
 612			}
 613		}
 614		spin_unlock(&ci->i_ceph_lock);
 615		WARN_ON(!found);
 616	}
 617	if (end > page_offset(page) + PAGE_SIZE)
 618		end = page_offset(page) + PAGE_SIZE;
 619	return end > start ? end - start : 0;
 620}
 621
 622/*
 623 * do a synchronous write on N pages
 624 */
 625static int ceph_sync_writepages(struct ceph_fs_client *fsc,
 626				struct ceph_vino vino,
 627				struct ceph_file_layout *layout,
 628				struct ceph_snap_context *snapc,
 629				u64 off, u64 len,
 630				u32 truncate_seq, u64 truncate_size,
 631				struct timespec64 *mtime,
 632				struct page **pages, int num_pages)
 633{
 634	struct ceph_osd_client *osdc = &fsc->client->osdc;
 635	struct ceph_osd_request *req;
 636	int rc = 0;
 637	int page_align = off & ~PAGE_MASK;
 638
 639	req = ceph_osdc_new_request(osdc, layout, vino, off, &len, 0, 1,
 640				    CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
 641				    snapc, truncate_seq, truncate_size,
 642				    true);
 643	if (IS_ERR(req))
 644		return PTR_ERR(req);
 645
 646	/* it may be a short write due to an object boundary */
 647	osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_align,
 648				false, false);
 649	dout("writepages %llu~%llu (%llu bytes)\n", off, len, len);
 650
 651	req->r_mtime = *mtime;
 652	rc = ceph_osdc_start_request(osdc, req, true);
 653	if (!rc)
 654		rc = ceph_osdc_wait_request(osdc, req);
 655
 656	ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
 657				  req->r_end_latency, rc);
 658
 659	ceph_osdc_put_request(req);
 660	if (rc == 0)
 661		rc = len;
 662	dout("writepages result %d\n", rc);
 663	return rc;
 664}
 665
 666/*
 667 * Write a single page, but leave the page locked.
 668 *
 669 * If we get a write error, mark the mapping for error, but still adjust the
 670 * dirty page accounting (i.e., page is no longer dirty).
 671 */
 672static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
 673{
 674	struct inode *inode;
 675	struct ceph_inode_info *ci;
 676	struct ceph_fs_client *fsc;
 
 677	struct ceph_snap_context *snapc, *oldest;
 678	loff_t page_off = page_offset(page);
 679	int err, len = PAGE_SIZE;
 680	struct ceph_writeback_ctl ceph_wbc;
 
 
 681
 682	dout("writepage %p idx %lu\n", page, page->index);
 683
 
 
 
 
 684	inode = page->mapping->host;
 685	ci = ceph_inode(inode);
 686	fsc = ceph_inode_to_client(inode);
 
 687
 688	/* verify this is a writeable snap context */
 689	snapc = page_snap_context(page);
 690	if (!snapc) {
 691		dout("writepage %p page %p not dirty?\n", inode, page);
 692		return 0;
 693	}
 694	oldest = get_oldest_context(inode, &ceph_wbc, snapc);
 695	if (snapc->seq > oldest->seq) {
 696		dout("writepage %p page %p snapc %p not writeable - noop\n",
 697		     inode, page, snapc);
 698		/* we should only noop if called by kswapd */
 699		WARN_ON(!(current->flags & PF_MEMALLOC));
 700		ceph_put_snap_context(oldest);
 701		redirty_page_for_writepage(wbc, page);
 702		return 0;
 703	}
 704	ceph_put_snap_context(oldest);
 705
 
 
 
 
 
 
 
 706	/* is this a partial page at end of file? */
 707	if (page_off >= ceph_wbc.i_size) {
 708		dout("%p page eof %llu\n", page, ceph_wbc.i_size);
 709		page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
 710		return 0;
 711	}
 
 
 712
 713	if (ceph_wbc.i_size < page_off + len)
 714		len = ceph_wbc.i_size - page_off;
 715
 716	dout("writepage %p page %p index %lu on %llu~%u snapc %p seq %lld\n",
 717	     inode, page, page->index, page_off, len, snapc, snapc->seq);
 718
 719	if (atomic_long_inc_return(&fsc->writeback_count) >
 720	    CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
 721		set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
 
 
 722
 723	set_page_writeback(page);
 724	err = ceph_sync_writepages(fsc, ceph_vino(inode),
 725				   &ci->i_layout, snapc, page_off, len,
 726				   ceph_wbc.truncate_seq,
 727				   ceph_wbc.truncate_size,
 728				   &inode->i_mtime, &page, 1);
 729	if (err < 0) {
 730		struct writeback_control tmp_wbc;
 731		if (!wbc)
 732			wbc = &tmp_wbc;
 733		if (err == -ERESTARTSYS) {
 734			/* killed by SIGKILL */
 735			dout("writepage interrupted page %p\n", page);
 736			redirty_page_for_writepage(wbc, page);
 737			end_page_writeback(page);
 738			return err;
 739		}
 740		if (err == -EBLACKLISTED)
 741			fsc->blacklisted = true;
 742		dout("writepage setting page/mapping error %d %p\n",
 743		     err, page);
 744		mapping_set_error(&inode->i_data, err);
 745		wbc->pages_skipped++;
 
 746	} else {
 747		dout("writepage cleaned page %p\n", page);
 748		err = 0;  /* vfs expects us to return 0 */
 749	}
 750	page->private = 0;
 751	ClearPagePrivate(page);
 752	end_page_writeback(page);
 753	ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
 754	ceph_put_snap_context(snapc);  /* page's reference */
 755
 756	if (atomic_long_dec_return(&fsc->writeback_count) <
 757	    CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
 758		clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
 759
 760	return err;
 761}
 762
 763static int ceph_writepage(struct page *page, struct writeback_control *wbc)
 764{
 765	int err;
 766	struct inode *inode = page->mapping->host;
 767	BUG_ON(!inode);
 768	ihold(inode);
 769	err = writepage_nounlock(page, wbc);
 770	if (err == -ERESTARTSYS) {
 771		/* direct memory reclaimer was killed by SIGKILL. return 0
 772		 * to prevent caller from setting mapping/page error */
 773		err = 0;
 774	}
 775	unlock_page(page);
 776	iput(inode);
 777	return err;
 778}
 779
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 780/*
 781 * async writeback completion handler.
 782 *
 783 * If we get an error, set the mapping error bit, but not the individual
 784 * page error bits.
 785 */
 786static void writepages_finish(struct ceph_osd_request *req)
 
 787{
 788	struct inode *inode = req->r_inode;
 789	struct ceph_inode_info *ci = ceph_inode(inode);
 790	struct ceph_osd_data *osd_data;
 
 791	struct page *page;
 792	int num_pages, total_pages = 0;
 793	int i, j;
 794	int rc = req->r_result;
 795	struct ceph_snap_context *snapc = req->r_snapc;
 796	struct address_space *mapping = inode->i_mapping;
 
 
 797	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 798	bool remove_page;
 
 799
 800	dout("writepages_finish %p rc %d\n", inode, rc);
 801	if (rc < 0) {
 802		mapping_set_error(mapping, rc);
 803		ceph_set_error_write(ci);
 804		if (rc == -EBLACKLISTED)
 805			fsc->blacklisted = true;
 
 
 
 
 
 
 806	} else {
 807		ceph_clear_error_write(ci);
 
 808	}
 809
 810	ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
 811				  req->r_end_latency, rc);
 812
 813	/*
 814	 * We lost the cache cap, need to truncate the page before
 815	 * it is unlocked, otherwise we'd truncate it later in the
 816	 * page truncation thread, possibly losing some data that
 817	 * raced its way in
 818	 */
 819	remove_page = !(ceph_caps_issued(ci) &
 820			(CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO));
 821
 822	/* clean all pages */
 823	for (i = 0; i < req->r_num_ops; i++) {
 824		if (req->r_ops[i].op != CEPH_OSD_OP_WRITE)
 825			break;
 
 826
 827		osd_data = osd_req_op_extent_osd_data(req, i);
 828		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 829		num_pages = calc_pages_for((u64)osd_data->alignment,
 830					   (u64)osd_data->length);
 831		total_pages += num_pages;
 832		for (j = 0; j < num_pages; j++) {
 833			page = osd_data->pages[j];
 834			BUG_ON(!page);
 835			WARN_ON(!PageUptodate(page));
 836
 837			if (atomic_long_dec_return(&fsc->writeback_count) <
 838			     CONGESTION_OFF_THRESH(
 839					fsc->mount_options->congestion_kb))
 840				clear_bdi_congested(inode_to_bdi(inode),
 841						    BLK_RW_ASYNC);
 842
 843			ceph_put_snap_context(page_snap_context(page));
 844			page->private = 0;
 845			ClearPagePrivate(page);
 846			dout("unlocking %p\n", page);
 847			end_page_writeback(page);
 848
 849			if (remove_page)
 850				generic_error_remove_page(inode->i_mapping,
 851							  page);
 852
 853			unlock_page(page);
 854		}
 855		dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
 856		     inode, osd_data->length, rc >= 0 ? num_pages : 0);
 
 
 
 
 857
 858		release_pages(osd_data->pages, num_pages);
 859	}
 
 
 860
 861	ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
 862
 863	osd_data = osd_req_op_extent_osd_data(req, 0);
 864	if (osd_data->pages_from_pool)
 865		mempool_free(osd_data->pages, ceph_wb_pagevec_pool);
 
 866	else
 867		kfree(osd_data->pages);
 868	ceph_osdc_put_request(req);
 869}
 870
 871/*
 872 * initiate async writeback
 873 */
 874static int ceph_writepages_start(struct address_space *mapping,
 875				 struct writeback_control *wbc)
 876{
 877	struct inode *inode = mapping->host;
 878	struct ceph_inode_info *ci = ceph_inode(inode);
 879	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 880	struct ceph_vino vino = ceph_vino(inode);
 881	pgoff_t index, start_index, end = -1;
 
 
 
 882	struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
 883	struct pagevec pvec;
 
 884	int rc = 0;
 885	unsigned int wsize = i_blocksize(inode);
 886	struct ceph_osd_request *req = NULL;
 887	struct ceph_writeback_ctl ceph_wbc;
 888	bool should_loop, range_whole = false;
 889	bool done = false;
 890
 891	dout("writepages_start %p (mode=%s)\n", inode,
 
 
 
 
 
 
 
 
 
 892	     wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
 893	     (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
 894
 895	if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
 896		if (ci->i_wrbuffer_ref > 0) {
 897			pr_warn_ratelimited(
 898				"writepage_start %p %lld forced umount\n",
 899				inode, ceph_ino(inode));
 900		}
 901		mapping_set_error(mapping, -EIO);
 902		return -EIO; /* we're in a forced umount, don't write! */
 903	}
 904	if (fsc->mount_options->wsize < wsize)
 905		wsize = fsc->mount_options->wsize;
 906
 907	pagevec_init(&pvec);
 908
 909	start_index = wbc->range_cyclic ? mapping->writeback_index : 0;
 910	index = start_index;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 911
 912retry:
 913	/* find oldest snap context with dirty data */
 914	snapc = get_oldest_context(inode, &ceph_wbc, NULL);
 
 
 915	if (!snapc) {
 916		/* hmm, why does writepages get called when there
 917		   is no dirty data? */
 918		dout(" no snap context with dirty data?\n");
 919		goto out;
 920	}
 
 
 921	dout(" oldest snapc is %p seq %lld (%d snaps)\n",
 922	     snapc, snapc->seq, snapc->num_snaps);
 923
 924	should_loop = false;
 925	if (ceph_wbc.head_snapc && snapc != last_snapc) {
 926		/* where to start/end? */
 927		if (wbc->range_cyclic) {
 928			index = start_index;
 929			end = -1;
 930			if (index > 0)
 931				should_loop = true;
 932			dout(" cyclic, start at %lu\n", index);
 933		} else {
 934			index = wbc->range_start >> PAGE_SHIFT;
 935			end = wbc->range_end >> PAGE_SHIFT;
 936			if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 937				range_whole = true;
 938			dout(" not cyclic, %lu to %lu\n", index, end);
 939		}
 940	} else if (!ceph_wbc.head_snapc) {
 941		/* Do not respect wbc->range_{start,end}. Dirty pages
 942		 * in that range can be associated with newer snapc.
 943		 * They are not writeable until we write all dirty pages
 944		 * associated with 'snapc' get written */
 945		if (index > 0)
 946			should_loop = true;
 947		dout(" non-head snapc, range whole\n");
 948	}
 949
 950	ceph_put_snap_context(last_snapc);
 
 
 
 
 
 
 951	last_snapc = snapc;
 952
 953	while (!done && index <= end) {
 954		int num_ops = 0, op_idx;
 955		unsigned i, pvec_pages, max_pages, locked_pages = 0;
 956		struct page **pages = NULL, **data_pages;
 
 
 
 
 957		struct page *page;
 958		pgoff_t strip_unit_end = 0;
 959		u64 offset = 0, len = 0;
 960		bool from_pool = false;
 961
 962		max_pages = wsize >> PAGE_SHIFT;
 
 
 963
 964get_more_pages:
 965		pvec_pages = pagevec_lookup_range_nr_tag(&pvec, mapping, &index,
 966						end, PAGECACHE_TAG_DIRTY,
 967						max_pages - locked_pages);
 968		dout("pagevec_lookup_range_tag got %d\n", pvec_pages);
 
 
 
 
 
 969		if (!pvec_pages && !locked_pages)
 970			break;
 971		for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
 972			page = pvec.pages[i];
 973			dout("? %p idx %lu\n", page, page->index);
 974			if (locked_pages == 0)
 975				lock_page(page);  /* first page */
 976			else if (!trylock_page(page))
 977				break;
 978
 979			/* only dirty pages, or our accounting breaks */
 980			if (unlikely(!PageDirty(page)) ||
 981			    unlikely(page->mapping != mapping)) {
 982				dout("!dirty or !mapping %p\n", page);
 983				unlock_page(page);
 984				continue;
 985			}
 986			/* only if matching snap context */
 987			pgsnapc = page_snap_context(page);
 988			if (pgsnapc != snapc) {
 989				dout("page snapc %p %lld != oldest %p %lld\n",
 990				     pgsnapc, pgsnapc->seq, snapc, snapc->seq);
 991				if (!should_loop &&
 992				    !ceph_wbc.head_snapc &&
 993				    wbc->sync_mode != WB_SYNC_NONE)
 994					should_loop = true;
 995				unlock_page(page);
 996				continue;
 997			}
 998			if (page_offset(page) >= ceph_wbc.i_size) {
 999				dout("%p page eof %llu\n",
1000				     page, ceph_wbc.i_size);
1001				if ((ceph_wbc.size_stable ||
1002				    page_offset(page) >= i_size_read(inode)) &&
1003				    clear_page_dirty_for_io(page))
1004					mapping->a_ops->invalidatepage(page,
1005								0, PAGE_SIZE);
1006				unlock_page(page);
1007				continue;
 
 
 
 
1008			}
1009			if (strip_unit_end && (page->index > strip_unit_end)) {
1010				dout("end of strip unit %p\n", page);
 
1011				unlock_page(page);
1012				break;
1013			}
1014			if (PageWriteback(page)) {
1015				if (wbc->sync_mode == WB_SYNC_NONE) {
1016					dout("%p under writeback\n", page);
1017					unlock_page(page);
1018					continue;
1019				}
1020				dout("waiting on writeback %p\n", page);
1021				wait_on_page_writeback(page);
 
 
 
 
 
 
 
1022			}
1023
1024			if (!clear_page_dirty_for_io(page)) {
1025				dout("%p !clear_page_dirty_for_io\n", page);
1026				unlock_page(page);
1027				continue;
1028			}
1029
1030			/*
1031			 * We have something to write.  If this is
1032			 * the first locked page this time through,
1033			 * calculate max possinle write size and
1034			 * allocate a page array
1035			 */
1036			if (locked_pages == 0) {
1037				u64 objnum;
1038				u64 objoff;
1039				u32 xlen;
1040
1041				/* prepare async write request */
1042				offset = (u64)page_offset(page);
1043				ceph_calc_file_object_mapping(&ci->i_layout,
1044							      offset, wsize,
1045							      &objnum, &objoff,
1046							      &xlen);
1047				len = xlen;
1048
1049				num_ops = 1;
1050				strip_unit_end = page->index +
1051					((len - 1) >> PAGE_SHIFT);
 
 
 
 
 
 
 
 
1052
1053				BUG_ON(pages);
1054				max_pages = calc_pages_for(0, (u64)len);
1055				pages = kmalloc_array(max_pages,
1056						      sizeof(*pages),
1057						      GFP_NOFS);
1058				if (!pages) {
1059					from_pool = true;
1060					pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
1061					BUG_ON(!pages);
1062				}
1063
1064				len = 0;
1065			} else if (page->index !=
1066				   (offset + len) >> PAGE_SHIFT) {
1067				if (num_ops >= (from_pool ?  CEPH_OSD_SLAB_OPS :
1068							     CEPH_OSD_MAX_OPS)) {
1069					redirty_page_for_writepage(wbc, page);
1070					unlock_page(page);
1071					break;
1072				}
1073
1074				num_ops++;
1075				offset = (u64)page_offset(page);
1076				len = 0;
1077			}
1078
1079			/* note position of first page in pvec */
 
 
1080			dout("%p will write page %p idx %lu\n",
1081			     inode, page, page->index);
1082
1083			if (atomic_long_inc_return(&fsc->writeback_count) >
1084			    CONGESTION_ON_THRESH(
 
1085				    fsc->mount_options->congestion_kb)) {
1086				set_bdi_congested(inode_to_bdi(inode),
1087						  BLK_RW_ASYNC);
1088			}
1089
1090
1091			pages[locked_pages++] = page;
1092			pvec.pages[i] = NULL;
1093
1094			len += PAGE_SIZE;
1095		}
1096
1097		/* did we get anything? */
1098		if (!locked_pages)
1099			goto release_pvec_pages;
1100		if (i) {
1101			unsigned j, n = 0;
1102			/* shift unused page to beginning of pvec */
1103			for (j = 0; j < pvec_pages; j++) {
1104				if (!pvec.pages[j])
1105					continue;
1106				if (n < j)
1107					pvec.pages[n] = pvec.pages[j];
1108				n++;
1109			}
1110			pvec.nr = n;
1111
1112			if (pvec_pages && i == pvec_pages &&
1113			    locked_pages < max_pages) {
1114				dout("reached end pvec, trying for more\n");
1115				pagevec_release(&pvec);
1116				goto get_more_pages;
1117			}
 
 
 
 
 
 
 
 
 
1118		}
1119
1120new_request:
1121		offset = page_offset(pages[0]);
1122		len = wsize;
1123
1124		req = ceph_osdc_new_request(&fsc->client->osdc,
1125					&ci->i_layout, vino,
1126					offset, &len, 0, num_ops,
1127					CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1128					snapc, ceph_wbc.truncate_seq,
1129					ceph_wbc.truncate_size, false);
1130		if (IS_ERR(req)) {
1131			req = ceph_osdc_new_request(&fsc->client->osdc,
1132						&ci->i_layout, vino,
1133						offset, &len, 0,
1134						min(num_ops,
1135						    CEPH_OSD_SLAB_OPS),
1136						CEPH_OSD_OP_WRITE,
1137						CEPH_OSD_FLAG_WRITE,
1138						snapc, ceph_wbc.truncate_seq,
1139						ceph_wbc.truncate_size, true);
1140			BUG_ON(IS_ERR(req));
1141		}
1142		BUG_ON(len < page_offset(pages[locked_pages - 1]) +
1143			     PAGE_SIZE - offset);
1144
1145		req->r_callback = writepages_finish;
1146		req->r_inode = inode;
1147
1148		/* Format the osd request message and submit the write */
1149		len = 0;
1150		data_pages = pages;
1151		op_idx = 0;
1152		for (i = 0; i < locked_pages; i++) {
1153			u64 cur_offset = page_offset(pages[i]);
1154			if (offset + len != cur_offset) {
1155				if (op_idx + 1 == req->r_num_ops)
1156					break;
1157				osd_req_op_extent_dup_last(req, op_idx,
1158							   cur_offset - offset);
1159				dout("writepages got pages at %llu~%llu\n",
1160				     offset, len);
1161				osd_req_op_extent_osd_data_pages(req, op_idx,
1162							data_pages, len, 0,
1163							from_pool, false);
1164				osd_req_op_extent_update(req, op_idx, len);
1165
1166				len = 0;
1167				offset = cur_offset; 
1168				data_pages = pages + i;
1169				op_idx++;
1170			}
1171
1172			set_page_writeback(pages[i]);
1173			len += PAGE_SIZE;
1174		}
1175
1176		if (ceph_wbc.size_stable) {
1177			len = min(len, ceph_wbc.i_size - offset);
1178		} else if (i == locked_pages) {
1179			/* writepages_finish() clears writeback pages
1180			 * according to the data length, so make sure
1181			 * data length covers all locked pages */
1182			u64 min_len = len + 1 - PAGE_SIZE;
1183			len = get_writepages_data_length(inode, pages[i - 1],
1184							 offset);
1185			len = max(len, min_len);
1186		}
1187		dout("writepages got pages at %llu~%llu\n", offset, len);
1188
1189		osd_req_op_extent_osd_data_pages(req, op_idx, data_pages, len,
1190						 0, from_pool, false);
1191		osd_req_op_extent_update(req, op_idx, len);
1192
1193		BUG_ON(op_idx + 1 != req->r_num_ops);
1194
1195		from_pool = false;
1196		if (i < locked_pages) {
1197			BUG_ON(num_ops <= req->r_num_ops);
1198			num_ops -= req->r_num_ops;
1199			locked_pages -= i;
1200
1201			/* allocate new pages array for next request */
1202			data_pages = pages;
1203			pages = kmalloc_array(locked_pages, sizeof(*pages),
1204					      GFP_NOFS);
1205			if (!pages) {
1206				from_pool = true;
1207				pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
1208				BUG_ON(!pages);
1209			}
1210			memcpy(pages, data_pages + i,
1211			       locked_pages * sizeof(*pages));
1212			memset(data_pages + i, 0,
1213			       locked_pages * sizeof(*pages));
1214		} else {
1215			BUG_ON(num_ops != req->r_num_ops);
1216			index = pages[i - 1]->index + 1;
1217			/* request message now owns the pages array */
1218			pages = NULL;
1219		}
1220
1221		req->r_mtime = inode->i_mtime;
1222		rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
1223		BUG_ON(rc);
1224		req = NULL;
1225
1226		wbc->nr_to_write -= i;
1227		if (pages)
1228			goto new_request;
1229
1230		/*
1231		 * We stop writing back only if we are not doing
1232		 * integrity sync. In case of integrity sync we have to
1233		 * keep going until we have written all the pages
1234		 * we tagged for writeback prior to entering this loop.
1235		 */
1236		if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE)
1237			done = true;
1238
1239release_pvec_pages:
1240		dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
1241		     pvec.nr ? pvec.pages[0] : NULL);
1242		pagevec_release(&pvec);
 
 
 
1243	}
1244
1245	if (should_loop && !done) {
1246		/* more to do; loop back to beginning of file */
1247		dout("writepages looping back to beginning of file\n");
1248		end = start_index - 1; /* OK even when start_index == 0 */
1249
1250		/* to write dirty pages associated with next snapc,
1251		 * we need to wait until current writes complete */
1252		if (wbc->sync_mode != WB_SYNC_NONE &&
1253		    start_index == 0 && /* all dirty pages were checked */
1254		    !ceph_wbc.head_snapc) {
1255			struct page *page;
1256			unsigned i, nr;
1257			index = 0;
1258			while ((index <= end) &&
1259			       (nr = pagevec_lookup_tag(&pvec, mapping, &index,
1260						PAGECACHE_TAG_WRITEBACK))) {
1261				for (i = 0; i < nr; i++) {
1262					page = pvec.pages[i];
1263					if (page_snap_context(page) != snapc)
1264						continue;
1265					wait_on_page_writeback(page);
1266				}
1267				pagevec_release(&pvec);
1268				cond_resched();
1269			}
1270		}
1271
1272		start_index = 0;
1273		index = 0;
1274		goto retry;
1275	}
1276
1277	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1278		mapping->writeback_index = index;
1279
1280out:
1281	ceph_osdc_put_request(req);
1282	ceph_put_snap_context(last_snapc);
1283	dout("writepages dend - startone, rc = %d\n", rc);
 
1284	return rc;
1285}
1286
1287
1288
1289/*
1290 * See if a given @snapc is either writeable, or already written.
1291 */
1292static int context_is_writeable_or_written(struct inode *inode,
1293					   struct ceph_snap_context *snapc)
1294{
1295	struct ceph_snap_context *oldest = get_oldest_context(inode, NULL, NULL);
1296	int ret = !oldest || snapc->seq <= oldest->seq;
1297
1298	ceph_put_snap_context(oldest);
1299	return ret;
1300}
1301
1302/*
1303 * We are only allowed to write into/dirty the page if the page is
1304 * clean, or already dirty within the same snap context.
1305 *
1306 * called with page locked.
1307 * return success with page locked,
1308 * or any failure (incl -EAGAIN) with page unlocked.
1309 */
1310static int ceph_update_writeable_page(struct file *file,
1311			    loff_t pos, unsigned len,
1312			    struct page *page)
1313{
1314	struct inode *inode = file_inode(file);
1315	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1316	struct ceph_inode_info *ci = ceph_inode(inode);
1317	loff_t page_off = pos & PAGE_MASK;
1318	int pos_in_page = pos & ~PAGE_MASK;
 
1319	int end_in_page = pos_in_page + len;
1320	loff_t i_size;
1321	int r;
1322	struct ceph_snap_context *snapc, *oldest;
1323
1324	if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1325		dout(" page %p forced umount\n", page);
1326		unlock_page(page);
1327		return -EIO;
1328	}
1329
1330retry_locked:
1331	/* writepages currently holds page lock, but if we change that later, */
1332	wait_on_page_writeback(page);
1333
 
 
 
 
1334	snapc = page_snap_context(page);
1335	if (snapc && snapc != ci->i_head_snapc) {
1336		/*
1337		 * this page is already dirty in another (older) snap
1338		 * context!  is it writeable now?
1339		 */
1340		oldest = get_oldest_context(inode, NULL, NULL);
 
 
1341		if (snapc->seq > oldest->seq) {
1342			ceph_put_snap_context(oldest);
1343			dout(" page %p snapc %p not current or oldest\n",
1344			     page, snapc);
1345			/*
1346			 * queue for writeback, and wait for snapc to
1347			 * be writeable or written
1348			 */
1349			snapc = ceph_get_snap_context(snapc);
1350			unlock_page(page);
1351			ceph_queue_writeback(inode);
1352			r = wait_event_killable(ci->i_cap_wq,
1353			       context_is_writeable_or_written(inode, snapc));
1354			ceph_put_snap_context(snapc);
1355			if (r == -ERESTARTSYS)
1356				return r;
1357			return -EAGAIN;
1358		}
1359		ceph_put_snap_context(oldest);
1360
1361		/* yay, writeable, do it now (without dropping page lock) */
1362		dout(" page %p snapc %p not current, but oldest\n",
1363		     page, snapc);
1364		if (!clear_page_dirty_for_io(page))
1365			goto retry_locked;
1366		r = writepage_nounlock(page, NULL);
1367		if (r < 0)
1368			goto fail_unlock;
1369		goto retry_locked;
1370	}
1371
1372	if (PageUptodate(page)) {
1373		dout(" page %p already uptodate\n", page);
1374		return 0;
1375	}
1376
1377	/* full page? */
1378	if (pos_in_page == 0 && len == PAGE_SIZE)
1379		return 0;
1380
1381	/* past end of file? */
1382	i_size = i_size_read(inode);
 
 
 
 
 
 
1383
1384	if (page_off >= i_size ||
1385	    (pos_in_page == 0 && (pos+len) >= i_size &&
1386	     end_in_page - pos_in_page != PAGE_SIZE)) {
1387		dout(" zeroing %p 0 - %d and %d - %d\n",
1388		     page, pos_in_page, end_in_page, (int)PAGE_SIZE);
1389		zero_user_segments(page,
1390				   0, pos_in_page,
1391				   end_in_page, PAGE_SIZE);
1392		return 0;
1393	}
1394
1395	/* we need to read it. */
1396	r = ceph_do_readpage(file, page);
1397	if (r < 0) {
1398		if (r == -EINPROGRESS)
1399			return -EAGAIN;
1400		goto fail_unlock;
1401	}
1402	goto retry_locked;
1403fail_unlock:
 
 
 
1404	unlock_page(page);
1405	return r;
1406}
1407
1408/*
1409 * We are only allowed to write into/dirty the page if the page is
1410 * clean, or already dirty within the same snap context.
1411 */
1412static int ceph_write_begin(struct file *file, struct address_space *mapping,
1413			    loff_t pos, unsigned len, unsigned flags,
1414			    struct page **pagep, void **fsdata)
1415{
1416	struct inode *inode = file_inode(file);
1417	struct page *page;
1418	pgoff_t index = pos >> PAGE_SHIFT;
1419	int r;
1420
1421	do {
1422		/* get a page */
1423		page = grab_cache_page_write_begin(mapping, index, 0);
1424		if (!page)
1425			return -ENOMEM;
 
1426
1427		dout("write_begin file %p inode %p page %p %d~%d\n", file,
1428		     inode, page, (int)pos, (int)len);
1429
1430		r = ceph_update_writeable_page(file, pos, len, page);
1431		if (r < 0)
1432			put_page(page);
1433		else
1434			*pagep = page;
1435	} while (r == -EAGAIN);
1436
1437	return r;
1438}
1439
1440/*
1441 * we don't do anything in here that simple_write_end doesn't do
1442 * except adjust dirty page accounting
 
1443 */
1444static int ceph_write_end(struct file *file, struct address_space *mapping,
1445			  loff_t pos, unsigned len, unsigned copied,
1446			  struct page *page, void *fsdata)
1447{
1448	struct inode *inode = file_inode(file);
1449	bool check_cap = false;
 
 
 
1450
1451	dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1452	     inode, page, (int)pos, (int)copied, (int)len);
1453
1454	/* zero the stale part of the page if we did a short copy */
1455	if (!PageUptodate(page)) {
1456		if (copied < len) {
1457			copied = 0;
1458			goto out;
1459		}
1460		SetPageUptodate(page);
1461	}
1462
1463	/* did file size increase? */
1464	if (pos+copied > i_size_read(inode))
 
1465		check_cap = ceph_inode_set_size(inode, pos+copied);
1466
 
 
 
1467	set_page_dirty(page);
1468
1469out:
1470	unlock_page(page);
1471	put_page(page);
 
1472
1473	if (check_cap)
1474		ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1475
1476	return copied;
1477}
1478
1479/*
1480 * we set .direct_IO to indicate direct io is supported, but since we
1481 * intercept O_DIRECT reads and writes early, this function should
1482 * never get called.
1483 */
1484static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
 
 
1485{
1486	WARN_ON(1);
1487	return -EINVAL;
1488}
1489
1490const struct address_space_operations ceph_aops = {
1491	.readpage = ceph_readpage,
1492	.readpages = ceph_readpages,
1493	.writepage = ceph_writepage,
1494	.writepages = ceph_writepages_start,
1495	.write_begin = ceph_write_begin,
1496	.write_end = ceph_write_end,
1497	.set_page_dirty = ceph_set_page_dirty,
1498	.invalidatepage = ceph_invalidatepage,
1499	.releasepage = ceph_releasepage,
1500	.direct_IO = ceph_direct_io,
1501};
1502
1503static void ceph_block_sigs(sigset_t *oldset)
1504{
1505	sigset_t mask;
1506	siginitsetinv(&mask, sigmask(SIGKILL));
1507	sigprocmask(SIG_BLOCK, &mask, oldset);
1508}
1509
1510static void ceph_restore_sigs(sigset_t *oldset)
1511{
1512	sigprocmask(SIG_SETMASK, oldset, NULL);
1513}
1514
1515/*
1516 * vm ops
1517 */
1518static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
1519{
1520	struct vm_area_struct *vma = vmf->vma;
1521	struct inode *inode = file_inode(vma->vm_file);
1522	struct ceph_inode_info *ci = ceph_inode(inode);
1523	struct ceph_file_info *fi = vma->vm_file->private_data;
1524	struct page *pinned_page = NULL;
1525	loff_t off = vmf->pgoff << PAGE_SHIFT;
1526	int want, got, err;
1527	sigset_t oldset;
1528	vm_fault_t ret = VM_FAULT_SIGBUS;
1529
1530	ceph_block_sigs(&oldset);
1531
1532	dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1533	     inode, ceph_vinop(inode), off, (size_t)PAGE_SIZE);
1534	if (fi->fmode & CEPH_FILE_MODE_LAZY)
1535		want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1536	else
1537		want = CEPH_CAP_FILE_CACHE;
1538
1539	got = 0;
1540	err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_RD, want, -1,
1541			    &got, &pinned_page);
1542	if (err < 0)
1543		goto out_restore;
1544
 
 
 
1545	dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1546	     inode, off, (size_t)PAGE_SIZE, ceph_cap_string(got));
1547
1548	if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1549	    ci->i_inline_version == CEPH_INLINE_NONE) {
1550		CEPH_DEFINE_RW_CONTEXT(rw_ctx, got);
1551		ceph_add_rw_context(fi, &rw_ctx);
1552		ret = filemap_fault(vmf);
1553		ceph_del_rw_context(fi, &rw_ctx);
1554		dout("filemap_fault %p %llu~%zd drop cap refs %s ret %x\n",
1555			inode, off, (size_t)PAGE_SIZE,
1556				ceph_cap_string(got), ret);
1557	} else
1558		err = -EAGAIN;
1559
1560	if (pinned_page)
1561		put_page(pinned_page);
1562	ceph_put_cap_refs(ci, got);
1563
1564	if (err != -EAGAIN)
1565		goto out_restore;
1566
1567	/* read inline data */
1568	if (off >= PAGE_SIZE) {
1569		/* does not support inline data > PAGE_SIZE */
1570		ret = VM_FAULT_SIGBUS;
1571	} else {
1572		struct address_space *mapping = inode->i_mapping;
1573		struct page *page = find_or_create_page(mapping, 0,
1574						mapping_gfp_constraint(mapping,
1575						~__GFP_FS));
1576		if (!page) {
1577			ret = VM_FAULT_OOM;
1578			goto out_inline;
1579		}
1580		err = __ceph_do_getattr(inode, page,
1581					 CEPH_STAT_CAP_INLINE_DATA, true);
1582		if (err < 0 || off >= i_size_read(inode)) {
1583			unlock_page(page);
1584			put_page(page);
1585			ret = vmf_error(err);
1586			goto out_inline;
1587		}
1588		if (err < PAGE_SIZE)
1589			zero_user_segment(page, err, PAGE_SIZE);
1590		else
1591			flush_dcache_page(page);
1592		SetPageUptodate(page);
1593		vmf->page = page;
1594		ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1595out_inline:
1596		dout("filemap_fault %p %llu~%zd read inline data ret %x\n",
1597		     inode, off, (size_t)PAGE_SIZE, ret);
1598	}
1599out_restore:
1600	ceph_restore_sigs(&oldset);
1601	if (err < 0)
1602		ret = vmf_error(err);
1603
1604	return ret;
1605}
1606
1607/*
1608 * Reuse write_begin here for simplicity.
1609 */
1610static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
1611{
1612	struct vm_area_struct *vma = vmf->vma;
1613	struct inode *inode = file_inode(vma->vm_file);
1614	struct ceph_inode_info *ci = ceph_inode(inode);
1615	struct ceph_file_info *fi = vma->vm_file->private_data;
1616	struct ceph_cap_flush *prealloc_cf;
1617	struct page *page = vmf->page;
1618	loff_t off = page_offset(page);
1619	loff_t size = i_size_read(inode);
1620	size_t len;
1621	int want, got, err;
1622	sigset_t oldset;
1623	vm_fault_t ret = VM_FAULT_SIGBUS;
1624
1625	prealloc_cf = ceph_alloc_cap_flush();
1626	if (!prealloc_cf)
1627		return VM_FAULT_OOM;
1628
1629	sb_start_pagefault(inode->i_sb);
1630	ceph_block_sigs(&oldset);
1631
1632	if (ci->i_inline_version != CEPH_INLINE_NONE) {
1633		struct page *locked_page = NULL;
1634		if (off == 0) {
1635			lock_page(page);
1636			locked_page = page;
1637		}
1638		err = ceph_uninline_data(vma->vm_file, locked_page);
1639		if (locked_page)
1640			unlock_page(locked_page);
1641		if (err < 0)
1642			goto out_free;
1643	}
1644
1645	if (off + PAGE_SIZE <= size)
1646		len = PAGE_SIZE;
1647	else
1648		len = size & ~PAGE_MASK;
1649
1650	dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1651	     inode, ceph_vinop(inode), off, len, size);
1652	if (fi->fmode & CEPH_FILE_MODE_LAZY)
1653		want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1654	else
1655		want = CEPH_CAP_FILE_BUFFER;
1656
1657	got = 0;
1658	err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_WR, want, off + len,
1659			    &got, NULL);
1660	if (err < 0)
1661		goto out_free;
1662
 
 
 
1663	dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1664	     inode, off, len, ceph_cap_string(got));
1665
1666	/* Update time before taking page lock */
1667	file_update_time(vma->vm_file);
1668	inode_inc_iversion_raw(inode);
1669
1670	do {
1671		lock_page(page);
1672
1673		if (page_mkwrite_check_truncate(page, inode) < 0) {
1674			unlock_page(page);
1675			ret = VM_FAULT_NOPAGE;
1676			break;
1677		}
1678
1679		err = ceph_update_writeable_page(vma->vm_file, off, len, page);
1680		if (err >= 0) {
1681			/* success.  we'll keep the page locked. */
1682			set_page_dirty(page);
1683			ret = VM_FAULT_LOCKED;
1684		}
1685	} while (err == -EAGAIN);
1686
1687	if (ret == VM_FAULT_LOCKED ||
1688	    ci->i_inline_version != CEPH_INLINE_NONE) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1689		int dirty;
1690		spin_lock(&ci->i_ceph_lock);
1691		ci->i_inline_version = CEPH_INLINE_NONE;
1692		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1693					       &prealloc_cf);
1694		spin_unlock(&ci->i_ceph_lock);
1695		if (dirty)
1696			__mark_inode_dirty(inode, dirty);
1697	}
1698
1699	dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %x\n",
1700	     inode, off, len, ceph_cap_string(got), ret);
1701	ceph_put_cap_refs(ci, got);
1702out_free:
1703	ceph_restore_sigs(&oldset);
1704	sb_end_pagefault(inode->i_sb);
1705	ceph_free_cap_flush(prealloc_cf);
1706	if (err < 0)
1707		ret = vmf_error(err);
1708	return ret;
1709}
1710
1711void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1712			   char	*data, size_t len)
1713{
1714	struct address_space *mapping = inode->i_mapping;
1715	struct page *page;
1716
1717	if (locked_page) {
1718		page = locked_page;
1719	} else {
1720		if (i_size_read(inode) == 0)
1721			return;
1722		page = find_or_create_page(mapping, 0,
1723					   mapping_gfp_constraint(mapping,
1724					   ~__GFP_FS));
1725		if (!page)
1726			return;
1727		if (PageUptodate(page)) {
1728			unlock_page(page);
1729			put_page(page);
1730			return;
1731		}
1732	}
1733
1734	dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1735	     inode, ceph_vinop(inode), len, locked_page);
1736
1737	if (len > 0) {
1738		void *kaddr = kmap_atomic(page);
1739		memcpy(kaddr, data, len);
1740		kunmap_atomic(kaddr);
1741	}
1742
1743	if (page != locked_page) {
1744		if (len < PAGE_SIZE)
1745			zero_user_segment(page, len, PAGE_SIZE);
1746		else
1747			flush_dcache_page(page);
1748
1749		SetPageUptodate(page);
1750		unlock_page(page);
1751		put_page(page);
1752	}
1753}
1754
1755int ceph_uninline_data(struct file *filp, struct page *locked_page)
1756{
1757	struct inode *inode = file_inode(filp);
1758	struct ceph_inode_info *ci = ceph_inode(inode);
1759	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1760	struct ceph_osd_request *req;
1761	struct page *page = NULL;
1762	u64 len, inline_version;
1763	int err = 0;
1764	bool from_pagecache = false;
1765
1766	spin_lock(&ci->i_ceph_lock);
1767	inline_version = ci->i_inline_version;
1768	spin_unlock(&ci->i_ceph_lock);
1769
1770	dout("uninline_data %p %llx.%llx inline_version %llu\n",
1771	     inode, ceph_vinop(inode), inline_version);
1772
1773	if (inline_version == 1 || /* initial version, no data */
1774	    inline_version == CEPH_INLINE_NONE)
1775		goto out;
1776
1777	if (locked_page) {
1778		page = locked_page;
1779		WARN_ON(!PageUptodate(page));
1780	} else if (ceph_caps_issued(ci) &
1781		   (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1782		page = find_get_page(inode->i_mapping, 0);
1783		if (page) {
1784			if (PageUptodate(page)) {
1785				from_pagecache = true;
1786				lock_page(page);
1787			} else {
1788				put_page(page);
1789				page = NULL;
1790			}
1791		}
1792	}
1793
1794	if (page) {
1795		len = i_size_read(inode);
1796		if (len > PAGE_SIZE)
1797			len = PAGE_SIZE;
1798	} else {
1799		page = __page_cache_alloc(GFP_NOFS);
1800		if (!page) {
1801			err = -ENOMEM;
1802			goto out;
1803		}
1804		err = __ceph_do_getattr(inode, page,
1805					CEPH_STAT_CAP_INLINE_DATA, true);
1806		if (err < 0) {
1807			/* no inline data */
1808			if (err == -ENODATA)
1809				err = 0;
1810			goto out;
1811		}
1812		len = err;
1813	}
1814
1815	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1816				    ceph_vino(inode), 0, &len, 0, 1,
1817				    CEPH_OSD_OP_CREATE, CEPH_OSD_FLAG_WRITE,
1818				    NULL, 0, 0, false);
1819	if (IS_ERR(req)) {
1820		err = PTR_ERR(req);
1821		goto out;
1822	}
1823
1824	req->r_mtime = inode->i_mtime;
1825	err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1826	if (!err)
1827		err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1828	ceph_osdc_put_request(req);
1829	if (err < 0)
1830		goto out;
1831
1832	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1833				    ceph_vino(inode), 0, &len, 1, 3,
1834				    CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1835				    NULL, ci->i_truncate_seq,
1836				    ci->i_truncate_size, false);
1837	if (IS_ERR(req)) {
1838		err = PTR_ERR(req);
1839		goto out;
1840	}
1841
1842	osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1843
1844	{
1845		__le64 xattr_buf = cpu_to_le64(inline_version);
1846		err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1847					    "inline_version", &xattr_buf,
1848					    sizeof(xattr_buf),
1849					    CEPH_OSD_CMPXATTR_OP_GT,
1850					    CEPH_OSD_CMPXATTR_MODE_U64);
1851		if (err)
1852			goto out_put;
1853	}
1854
1855	{
1856		char xattr_buf[32];
1857		int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1858					 "%llu", inline_version);
1859		err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1860					    "inline_version",
1861					    xattr_buf, xattr_len, 0, 0);
1862		if (err)
1863			goto out_put;
1864	}
1865
1866	req->r_mtime = inode->i_mtime;
1867	err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1868	if (!err)
1869		err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1870
1871	ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
1872				  req->r_end_latency, err);
1873
1874out_put:
1875	ceph_osdc_put_request(req);
1876	if (err == -ECANCELED)
1877		err = 0;
1878out:
1879	if (page && page != locked_page) {
1880		if (from_pagecache) {
1881			unlock_page(page);
1882			put_page(page);
1883		} else
1884			__free_pages(page, 0);
1885	}
1886
1887	dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1888	     inode, ceph_vinop(inode), inline_version, err);
1889	return err;
1890}
1891
1892static const struct vm_operations_struct ceph_vmops = {
1893	.fault		= ceph_filemap_fault,
1894	.page_mkwrite	= ceph_page_mkwrite,
 
1895};
1896
1897int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1898{
1899	struct address_space *mapping = file->f_mapping;
1900
1901	if (!mapping->a_ops->readpage)
1902		return -ENOEXEC;
1903	file_accessed(file);
1904	vma->vm_ops = &ceph_vmops;
1905	return 0;
1906}
1907
1908enum {
1909	POOL_READ	= 1,
1910	POOL_WRITE	= 2,
1911};
1912
1913static int __ceph_pool_perm_get(struct ceph_inode_info *ci,
1914				s64 pool, struct ceph_string *pool_ns)
1915{
1916	struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1917	struct ceph_mds_client *mdsc = fsc->mdsc;
1918	struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1919	struct rb_node **p, *parent;
1920	struct ceph_pool_perm *perm;
1921	struct page **pages;
1922	size_t pool_ns_len;
1923	int err = 0, err2 = 0, have = 0;
1924
1925	down_read(&mdsc->pool_perm_rwsem);
1926	p = &mdsc->pool_perm_tree.rb_node;
1927	while (*p) {
1928		perm = rb_entry(*p, struct ceph_pool_perm, node);
1929		if (pool < perm->pool)
1930			p = &(*p)->rb_left;
1931		else if (pool > perm->pool)
1932			p = &(*p)->rb_right;
1933		else {
1934			int ret = ceph_compare_string(pool_ns,
1935						perm->pool_ns,
1936						perm->pool_ns_len);
1937			if (ret < 0)
1938				p = &(*p)->rb_left;
1939			else if (ret > 0)
1940				p = &(*p)->rb_right;
1941			else {
1942				have = perm->perm;
1943				break;
1944			}
1945		}
1946	}
1947	up_read(&mdsc->pool_perm_rwsem);
1948	if (*p)
1949		goto out;
1950
1951	if (pool_ns)
1952		dout("__ceph_pool_perm_get pool %lld ns %.*s no perm cached\n",
1953		     pool, (int)pool_ns->len, pool_ns->str);
1954	else
1955		dout("__ceph_pool_perm_get pool %lld no perm cached\n", pool);
1956
1957	down_write(&mdsc->pool_perm_rwsem);
1958	p = &mdsc->pool_perm_tree.rb_node;
1959	parent = NULL;
1960	while (*p) {
1961		parent = *p;
1962		perm = rb_entry(parent, struct ceph_pool_perm, node);
1963		if (pool < perm->pool)
1964			p = &(*p)->rb_left;
1965		else if (pool > perm->pool)
1966			p = &(*p)->rb_right;
1967		else {
1968			int ret = ceph_compare_string(pool_ns,
1969						perm->pool_ns,
1970						perm->pool_ns_len);
1971			if (ret < 0)
1972				p = &(*p)->rb_left;
1973			else if (ret > 0)
1974				p = &(*p)->rb_right;
1975			else {
1976				have = perm->perm;
1977				break;
1978			}
1979		}
1980	}
1981	if (*p) {
1982		up_write(&mdsc->pool_perm_rwsem);
1983		goto out;
1984	}
1985
1986	rd_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1987					 1, false, GFP_NOFS);
1988	if (!rd_req) {
1989		err = -ENOMEM;
1990		goto out_unlock;
1991	}
1992
1993	rd_req->r_flags = CEPH_OSD_FLAG_READ;
1994	osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1995	rd_req->r_base_oloc.pool = pool;
1996	if (pool_ns)
1997		rd_req->r_base_oloc.pool_ns = ceph_get_string(pool_ns);
1998	ceph_oid_printf(&rd_req->r_base_oid, "%llx.00000000", ci->i_vino.ino);
1999
2000	err = ceph_osdc_alloc_messages(rd_req, GFP_NOFS);
2001	if (err)
2002		goto out_unlock;
2003
2004	wr_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
2005					 1, false, GFP_NOFS);
2006	if (!wr_req) {
2007		err = -ENOMEM;
2008		goto out_unlock;
2009	}
2010
2011	wr_req->r_flags = CEPH_OSD_FLAG_WRITE;
2012	osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
2013	ceph_oloc_copy(&wr_req->r_base_oloc, &rd_req->r_base_oloc);
2014	ceph_oid_copy(&wr_req->r_base_oid, &rd_req->r_base_oid);
2015
2016	err = ceph_osdc_alloc_messages(wr_req, GFP_NOFS);
2017	if (err)
2018		goto out_unlock;
2019
2020	/* one page should be large enough for STAT data */
2021	pages = ceph_alloc_page_vector(1, GFP_KERNEL);
2022	if (IS_ERR(pages)) {
2023		err = PTR_ERR(pages);
2024		goto out_unlock;
2025	}
2026
2027	osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
2028				     0, false, true);
2029	err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
2030
2031	wr_req->r_mtime = ci->vfs_inode.i_mtime;
2032	err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
2033
2034	if (!err)
2035		err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
2036	if (!err2)
2037		err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
2038
2039	if (err >= 0 || err == -ENOENT)
2040		have |= POOL_READ;
2041	else if (err != -EPERM) {
2042		if (err == -EBLACKLISTED)
2043			fsc->blacklisted = true;
2044		goto out_unlock;
2045	}
2046
2047	if (err2 == 0 || err2 == -EEXIST)
2048		have |= POOL_WRITE;
2049	else if (err2 != -EPERM) {
2050		if (err2 == -EBLACKLISTED)
2051			fsc->blacklisted = true;
2052		err = err2;
2053		goto out_unlock;
2054	}
2055
2056	pool_ns_len = pool_ns ? pool_ns->len : 0;
2057	perm = kmalloc(sizeof(*perm) + pool_ns_len + 1, GFP_NOFS);
2058	if (!perm) {
2059		err = -ENOMEM;
2060		goto out_unlock;
2061	}
2062
2063	perm->pool = pool;
2064	perm->perm = have;
2065	perm->pool_ns_len = pool_ns_len;
2066	if (pool_ns_len > 0)
2067		memcpy(perm->pool_ns, pool_ns->str, pool_ns_len);
2068	perm->pool_ns[pool_ns_len] = 0;
2069
2070	rb_link_node(&perm->node, parent, p);
2071	rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
2072	err = 0;
2073out_unlock:
2074	up_write(&mdsc->pool_perm_rwsem);
2075
2076	ceph_osdc_put_request(rd_req);
2077	ceph_osdc_put_request(wr_req);
2078out:
2079	if (!err)
2080		err = have;
2081	if (pool_ns)
2082		dout("__ceph_pool_perm_get pool %lld ns %.*s result = %d\n",
2083		     pool, (int)pool_ns->len, pool_ns->str, err);
2084	else
2085		dout("__ceph_pool_perm_get pool %lld result = %d\n", pool, err);
2086	return err;
2087}
2088
2089int ceph_pool_perm_check(struct inode *inode, int need)
2090{
2091	struct ceph_inode_info *ci = ceph_inode(inode);
2092	struct ceph_string *pool_ns;
2093	s64 pool;
2094	int ret, flags;
2095
2096	if (ci->i_vino.snap != CEPH_NOSNAP) {
2097		/*
2098		 * Pool permission check needs to write to the first object.
2099		 * But for snapshot, head of the first object may have alread
2100		 * been deleted. Skip check to avoid creating orphan object.
2101		 */
2102		return 0;
2103	}
2104
2105	if (ceph_test_mount_opt(ceph_inode_to_client(inode),
2106				NOPOOLPERM))
2107		return 0;
2108
2109	spin_lock(&ci->i_ceph_lock);
2110	flags = ci->i_ceph_flags;
2111	pool = ci->i_layout.pool_id;
2112	spin_unlock(&ci->i_ceph_lock);
2113check:
2114	if (flags & CEPH_I_POOL_PERM) {
2115		if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
2116			dout("ceph_pool_perm_check pool %lld no read perm\n",
2117			     pool);
2118			return -EPERM;
2119		}
2120		if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
2121			dout("ceph_pool_perm_check pool %lld no write perm\n",
2122			     pool);
2123			return -EPERM;
2124		}
2125		return 0;
2126	}
2127
2128	pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
2129	ret = __ceph_pool_perm_get(ci, pool, pool_ns);
2130	ceph_put_string(pool_ns);
2131	if (ret < 0)
2132		return ret;
2133
2134	flags = CEPH_I_POOL_PERM;
2135	if (ret & POOL_READ)
2136		flags |= CEPH_I_POOL_RD;
2137	if (ret & POOL_WRITE)
2138		flags |= CEPH_I_POOL_WR;
2139
2140	spin_lock(&ci->i_ceph_lock);
2141	if (pool == ci->i_layout.pool_id &&
2142	    pool_ns == rcu_dereference_raw(ci->i_layout.pool_ns)) {
2143		ci->i_ceph_flags |= flags;
2144        } else {
2145		pool = ci->i_layout.pool_id;
2146		flags = ci->i_ceph_flags;
2147	}
2148	spin_unlock(&ci->i_ceph_lock);
2149	goto check;
2150}
2151
2152void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
2153{
2154	struct ceph_pool_perm *perm;
2155	struct rb_node *n;
2156
2157	while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
2158		n = rb_first(&mdsc->pool_perm_tree);
2159		perm = rb_entry(n, struct ceph_pool_perm, node);
2160		rb_erase(n, &mdsc->pool_perm_tree);
2161		kfree(perm);
2162	}
2163}