1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Lustre Lite I/O page cache routines shared by different kernel revs
6 * Copyright (c) 2001-2003 Cluster File Systems, Inc.
8 * This file is part of Lustre, http://www.lustre.org.
10 * Lustre is free software; you can redistribute it and/or
11 * modify it under the terms of version 2 of the GNU General Public
12 * License as published by the Free Software Foundation.
14 * Lustre is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with Lustre; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <linux/config.h>
25 #include <linux/kernel.h>
27 #include <linux/string.h>
28 #include <linux/stat.h>
29 #include <linux/errno.h>
30 #include <linux/smp_lock.h>
31 #include <linux/unistd.h>
32 #include <linux/version.h>
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
37 #include <linux/stat.h>
38 #include <asm/uaccess.h>
39 #include <asm/segment.h>
41 #include <linux/pagemap.h>
42 #include <linux/smp_lock.h>
44 #define DEBUG_SUBSYSTEM S_LLITE
46 #include <linux/lustre_mds.h>
47 #include <linux/lustre_lite.h>
48 #include "llite_internal.h"
49 #include <linux/lustre_compat25.h>
51 #ifndef list_for_each_prev_safe
52 #define list_for_each_prev_safe(pos, n, head) \
53 for (pos = (head)->prev, n = pos->prev; pos != (head); \
54 pos = n, n = pos->prev )
57 /* SYNCHRONOUS I/O to object storage for an inode */
58 static int ll_brw(int cmd, struct inode *inode, struct obdo *oa,
59 struct page *page, int flags)
61 struct ll_inode_info *lli = ll_i2info(inode);
62 struct lov_stripe_md *lsm = lli->lli_smd;
68 pg.off = ((obd_off)page->index) << PAGE_SHIFT;
70 if (cmd == OBD_BRW_WRITE && (pg.off + PAGE_SIZE > inode->i_size))
71 pg.count = inode->i_size % PAGE_SIZE;
75 CDEBUG(D_PAGE, "%s %d bytes ino %lu at "LPU64"/"LPX64"\n",
76 cmd & OBD_BRW_WRITE ? "write" : "read", pg.count, inode->i_ino,
79 CERROR("ZERO COUNT: ino %lu: size %p:%Lu(%p:%Lu) idx %lu off "
81 inode->i_ino, inode, inode->i_size, page->mapping->host,
82 page->mapping->host->i_size, page->index, pg.off);
87 if (cmd == OBD_BRW_WRITE)
88 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
89 LPROC_LL_BRW_WRITE, pg.count);
91 lprocfs_counter_add(ll_i2sbi(inode)->ll_stats,
92 LPROC_LL_BRW_READ, pg.count);
93 rc = obd_brw(cmd, ll_i2obdexp(inode), oa, lsm, 1, &pg, NULL);
95 obdo_to_inode(inode, oa, OBD_MD_FLBLOCKS);
97 CERROR("error from obd_brw: rc = %d\n", rc);
101 /* this isn't where truncate starts. roughly:
102 * sys_truncate->ll_setattr_raw->vmtruncate->ll_truncate
103 * we grab the lock back in setattr_raw to avoid races. */
104 void ll_truncate(struct inode *inode)
106 struct lov_stripe_md *lsm = ll_i2info(inode)->lli_smd;
110 CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p)\n", inode->i_ino,
111 inode->i_generation, inode);
113 /* object not yet allocated - this is handled in ll_setattr_raw */
115 CERROR("truncate on inode %lu with no objects\n", inode->i_ino);
120 oa.o_id = lsm->lsm_object_id;
121 oa.o_valid = OBD_MD_FLID;
122 obdo_from_inode(&oa, inode, OBD_MD_FLTYPE|OBD_MD_FLMODE|OBD_MD_FLATIME|
123 OBD_MD_FLMTIME | OBD_MD_FLCTIME);
125 CDEBUG(D_INFO, "calling punch for "LPX64" (all bytes after %Lu)\n",
126 oa.o_id, inode->i_size);
128 /* truncate == punch from new size to absolute end of file */
129 rc = obd_punch(ll_i2obdexp(inode), &oa, lsm, inode->i_size,
130 OBD_OBJECT_EOF, NULL);
132 CERROR("obd_truncate fails (%d) ino %lu\n", rc, inode->i_ino);
134 obdo_to_inode(inode, &oa, OBD_MD_FLSIZE | OBD_MD_FLBLOCKS |
135 OBD_MD_FLATIME | OBD_MD_FLMTIME |
142 int ll_prepare_write(struct file *file, struct page *page, unsigned from,
145 struct inode *inode = page->mapping->host;
146 struct ll_inode_info *lli = ll_i2info(inode);
147 struct lov_stripe_md *lsm = lli->lli_smd;
148 obd_off offset = ((obd_off)page->index) << PAGE_SHIFT;
154 if (!PageLocked(page))
157 if (PageUptodate(page))
160 /* Check to see if we should return -EIO right away */
163 pg.count = PAGE_SIZE;
165 rc = obd_brw(OBD_BRW_CHECK, ll_i2obdexp(inode), NULL, lsm, 1, &pg,
170 /* We're completely overwriting an existing page, so _don't_ set it up
171 * to date until commit_write */
172 if (from == 0 && to == PAGE_SIZE) {
173 POISON_PAGE(page, 0x11);
177 /* If are writing to a new page, no need to read old data.
178 * the extent locking and getattr procedures in ll_file_write have
179 * guaranteed that i_size is stable enough for our zeroing needs */
180 if (inode->i_size <= offset) {
181 memset(kmap(page), 0, PAGE_SIZE);
183 GOTO(prepare_done, rc = 0);
186 oa.o_id = lsm->lsm_object_id;
187 oa.o_mode = inode->i_mode;
188 oa.o_valid = OBD_MD_FLID | OBD_MD_FLMODE | OBD_MD_FLTYPE;
190 /* XXX could be an async ocp read.. read-ahead? */
191 rc = ll_brw(OBD_BRW_READ, inode, &oa, page, 0);
193 /* bug 1598: don't clobber blksize */
194 oa.o_valid &= ~(OBD_MD_FLSIZE | OBD_MD_FLBLKSZ);
195 obdo_refresh_inode(inode, &oa, oa.o_valid);
201 SetPageUptodate(page);
206 int ll_write_count(struct page *page)
208 struct inode *inode = page->mapping->host;
210 /* catch race with truncate */
211 if (((loff_t)page->index << PAGE_SHIFT) >= inode->i_size)
214 /* catch sub-page write at end of file */
215 if (((loff_t)page->index << PAGE_SHIFT) + PAGE_SIZE > inode->i_size)
216 return inode->i_size % PAGE_SIZE;
221 struct ll_async_page *llap_from_cookie(void *cookie)
223 struct ll_async_page *llap = cookie;
224 if (llap->llap_magic != LLAP_MAGIC)
225 return ERR_PTR(-EINVAL);
229 static int ll_ap_make_ready(void *data, int cmd)
231 struct ll_async_page *llap;
235 llap = llap_from_cookie(data);
239 page = llap->llap_page;
241 if (cmd == OBD_BRW_READ) {
242 /* paths that want to cancel a read-ahead clear page-private
243 * before locking the page */
244 if (test_and_clear_bit(PG_private, &page->flags))
249 /* we're trying to write, but the page is locked.. come back later */
250 if (TryLockPage(page))
253 LL_CDEBUG_PAGE(page, "made ready\n");
254 page_cache_get(page);
256 /* if we left PageDirty we might get another writepage call
257 * in the future. list walkers are bright enough
258 * to check page dirty so we can leave it on whatever list
259 * its on. XXX also, we're called with the cli list so if
260 * we got the page cache list we'd create a lock inversion
261 * with the removepage path which gets the page lock then the
263 clear_page_dirty(page);
267 static int ll_ap_refresh_count(void *data, int cmd)
269 struct ll_async_page *llap;
272 /* readpage queues with _COUNT_STABLE, shouldn't get here. */
273 LASSERT(cmd != OBD_BRW_READ);
275 llap = llap_from_cookie(data);
277 RETURN(PTR_ERR(llap));
279 return ll_write_count(llap->llap_page);
282 void ll_inode_fill_obdo(struct inode *inode, int cmd, struct obdo *oa)
284 struct lov_stripe_md *lsm;
285 obd_flag valid_flags;
287 lsm = ll_i2info(inode)->lli_smd;
289 oa->o_id = lsm->lsm_object_id;
290 oa->o_valid = OBD_MD_FLID;
291 valid_flags = OBD_MD_FLTYPE | OBD_MD_FLATIME;
292 if (cmd == OBD_BRW_WRITE) {
293 oa->o_valid |= OBD_MD_FLIFID | OBD_MD_FLEPOCH;
294 mdc_pack_fid(obdo_fid(oa), inode->i_ino, 0, inode->i_mode);
295 oa->o_easize = ll_i2info(inode)->lli_io_epoch;
297 valid_flags |= OBD_MD_FLMTIME | OBD_MD_FLCTIME;
300 obdo_from_inode(oa, inode, valid_flags);
303 static void ll_ap_fill_obdo(void *data, int cmd, struct obdo *oa)
305 struct ll_async_page *llap;
308 llap = llap_from_cookie(data);
314 ll_inode_fill_obdo(llap->llap_page->mapping->host, cmd, oa);
318 static struct obd_async_page_ops ll_async_page_ops = {
319 .ap_make_ready = ll_ap_make_ready,
320 .ap_refresh_count = ll_ap_refresh_count,
321 .ap_fill_obdo = ll_ap_fill_obdo,
322 .ap_completion = ll_ap_completion,
325 /* XXX have the exp be an argument? */
326 struct ll_async_page *llap_from_page(struct page *page)
328 struct ll_async_page *llap;
329 struct obd_export *exp;
330 struct inode *inode = page->mapping->host;
331 struct ll_sb_info *sbi = ll_i2sbi(inode);
335 if (page->private != 0) {
336 llap = (struct ll_async_page *)page->private;
337 if (llap->llap_magic != LLAP_MAGIC)
338 RETURN(ERR_PTR(-EINVAL));
342 exp = ll_i2obdexp(page->mapping->host);
344 RETURN(ERR_PTR(-EINVAL));
346 OBD_ALLOC(llap, sizeof(*llap));
347 llap->llap_magic = LLAP_MAGIC;
348 rc = obd_prep_async_page(exp, ll_i2info(inode)->lli_smd,
350 (obd_off)page->index << PAGE_SHIFT,
351 &ll_async_page_ops, llap, &llap->llap_cookie);
353 OBD_FREE(llap, sizeof(*llap));
357 CDEBUG(D_CACHE, "llap %p page %p cookie %p obj off "LPU64"\n", llap,
358 page, llap->llap_cookie, (obd_off)page->index << PAGE_SHIFT);
359 page->private = (unsigned long)llap;
360 llap->llap_page = page;
362 spin_lock(&sbi->ll_pglist_lock);
363 sbi->ll_pglist_gen++;
364 list_add_tail(&llap->llap_proc_item, &sbi->ll_pglist);
365 spin_unlock(&sbi->ll_pglist_lock);
370 /* update our write count to account for i_size increases that may have
371 * happened since we've queued the page for io. */
373 /* be careful not to return success without setting the page Uptodate or
374 * the next pass through prepare_write will read in stale data from disk. */
375 int ll_commit_write(struct file *file, struct page *page, unsigned from,
378 struct inode *inode = page->mapping->host;
379 struct ll_inode_info *lli = ll_i2info(inode);
380 struct lov_stripe_md *lsm = lli->lli_smd;
381 struct obd_export *exp = NULL;
382 struct ll_async_page *llap;
387 SIGNAL_MASK_ASSERT(); /* XXX BUG 1511 */
388 LASSERT(inode == file->f_dentry->d_inode);
389 LASSERT(PageLocked(page));
391 CDEBUG(D_INODE, "inode %p is writing page %p from %d to %d at %lu\n",
392 inode, page, from, to, page->index);
394 llap = llap_from_page(page);
396 RETURN(PTR_ERR(llap));
398 /* queue a write for some time in the future the first time we
400 if (!PageDirty(page)) {
401 lprocfs_counter_incr(ll_i2sbi(inode)->ll_stats,
402 LPROC_LL_DIRTY_MISSES);
404 exp = ll_i2obdexp(inode);
408 /* _make_ready only sees llap once we've unlocked the page */
409 llap->llap_write_queued = 1;
410 rc = obd_queue_async_io(exp, lsm, NULL, llap->llap_cookie,
411 OBD_BRW_WRITE, 0, 0, 0, 0);
412 if (rc != 0) { /* async failed, try sync.. */
413 struct obd_sync_io_container *osic;
416 llap->llap_write_queued = 0;
417 rc = obd_queue_sync_io(exp, lsm, NULL, osic,
419 OBD_BRW_WRITE, 0, to, 0);
423 rc = obd_trigger_sync_io(exp, lsm, NULL, osic);
427 rc = osic_wait(osic);
432 LL_CDEBUG_PAGE(page, "write queued\n");
433 //llap_write_pending(inode, llap);
435 lprocfs_counter_incr(ll_i2sbi(inode)->ll_stats,
436 LPROC_LL_DIRTY_HITS);
439 /* put the page in the page cache, from now on ll_removepage is
440 * responsible for cleaning up the llap */
441 set_page_dirty(page);
445 /* XXX needs to be pushed down to the OSC as EOC */
446 size = (((obd_off)page->index) << PAGE_SHIFT) + to;
447 if (size > inode->i_size) {
448 inode->i_size = size;
449 /* see commentary in file.c:ll_inode_getattr() */
450 set_bit(LLI_F_PREFER_EXTENDED_SIZE, &lli->lli_flags);
452 SetPageUptodate(page);
457 /* the kernel calls us here when a page is unhashed from the page cache.
458 * the page will be locked and the kernel is holding a spinlock, so
459 * we need to be careful. we're just tearing down our book-keeping
461 void ll_removepage(struct page *page)
463 struct inode *inode = page->mapping->host;
464 struct obd_export *exp;
465 struct ll_async_page *llap;
466 struct ll_sb_info *sbi = ll_i2sbi(inode);
470 LASSERT(!in_interrupt());
472 /* sync pages or failed read pages can leave pages in the page
473 * cache that don't have our data associated with them anymore */
474 if (page->private == 0) {
479 LL_CDEBUG_PAGE(page, "being evicted\n");
481 exp = ll_i2obdexp(inode);
483 CERROR("page %p ind %lu gave null export\n", page,
489 llap = llap_from_page(page);
491 CERROR("page %p ind %lu couldn't find llap: %ld\n", page,
492 page->index, PTR_ERR(llap));
497 //llap_write_complete(inode, llap);
498 rc = obd_teardown_async_page(exp, ll_i2info(inode)->lli_smd, NULL,
501 CERROR("page %p ind %lu failed: %d\n", page, page->index, rc);
503 /* this unconditional free is only safe because the page lock
504 * is providing exclusivity to memory pressure/truncate/writeback..*/
507 spin_lock(&sbi->ll_pglist_lock);
508 if (!list_empty(&llap->llap_proc_item))
509 list_del_init(&llap->llap_proc_item);
510 sbi->ll_pglist_gen++;
511 spin_unlock(&sbi->ll_pglist_lock);
512 OBD_FREE(llap, sizeof(*llap));
516 static int ll_page_matches(struct page *page)
518 struct lustre_handle match_lockh = {0};
519 struct inode *inode = page->mapping->host;
520 struct ldlm_extent page_extent;
524 page_extent.start = (__u64)page->index << PAGE_CACHE_SHIFT;
525 page_extent.end = page_extent.start + PAGE_CACHE_SIZE - 1;
526 flags = LDLM_FL_CBPENDING | LDLM_FL_BLOCK_GRANTED;
527 matches = obd_match(ll_i2sbi(inode)->ll_osc_exp,
528 ll_i2info(inode)->lli_smd, LDLM_EXTENT,
529 &page_extent, sizeof(page_extent),
530 LCK_PR, &flags, inode, &match_lockh);
532 LL_CDEBUG_PAGE(page, "lock match failed\n");
536 obd_cancel(ll_i2sbi(inode)->ll_osc_exp,
537 ll_i2info(inode)->lli_smd, LCK_PR, &match_lockh);
542 static int ll_issue_page_read(struct obd_export *exp,
543 struct ll_async_page *llap,
546 struct page *page = llap->llap_page;
549 /* we don't issue this page as URGENT so that it can be batched
550 * with other pages by the kernel's read-ahead. We have a strong
551 * requirement that readpage() callers must call wait_on_page()
552 * or lock_page() to get into ->sync_page() to trigger the IO */
553 llap->llap_defer_uptodate = defer_uptodate;
554 page_cache_get(page);
555 SetPagePrivate(page);
556 rc = obd_queue_async_io(exp, ll_i2info(page->mapping->host)->lli_smd,
557 NULL, llap->llap_cookie, OBD_BRW_READ, 0,
558 PAGE_SIZE, 0, ASYNC_COUNT_STABLE);
560 LL_CDEBUG_PAGE(page, "read queueing failed\n");
561 ClearPagePrivate(page);
562 page_cache_release(page);
567 static void ll_readahead(struct ll_readahead_state *ras,
568 struct obd_export *exp, struct address_space *mapping)
570 unsigned long i, start, end;
571 struct ll_async_page *llap;
575 if (mapping->host->i_size == 0)
578 spin_lock(&ras->ras_lock);
580 /* make sure to issue a window's worth of read-ahead pages */
582 start = end - ras->ras_window;
586 /* but don't iterate over pages that we've already issued. this
587 * will set start to end + 1 if we've already read-ahead up to
588 * ras_last sothe for() won't be entered */
589 if (ras->ras_next_index > start)
590 start = ras->ras_next_index;
592 ras->ras_next_index = end + 1;
594 CDEBUG(D_READA, "ni %lu last %lu win %lu: reading from %lu to %lu\n",
595 ras->ras_next_index, ras->ras_last, ras->ras_window,
598 spin_unlock(&ras->ras_lock);
600 /* clamp to filesize */
601 i = (mapping->host->i_size - 1) >> PAGE_CACHE_SHIFT;
604 for (i = start; i <= end; i++) {
605 /* grab_cache_page_nowait returns null if this races with
606 * truncating the page (page->mapping == NULL) */
607 page = grab_cache_page_nowait(mapping, i);
611 /* the book-keeping above promises that we've tried
612 * all the indices from start to end, so we don't
613 * stop if anyone returns an error. This may not be good. */
614 if (Page_Uptodate(page) || ll_page_matches(page) <= 0)
617 llap = llap_from_page(page);
618 if (IS_ERR(llap) || llap->llap_defer_uptodate)
621 rc = ll_issue_page_read(exp, llap, 1);
623 LL_CDEBUG_PAGE(page, "started read-ahead\n");
626 LL_CDEBUG_PAGE(page, "skipping read-ahead\n");
630 page_cache_release(page);
634 /* XXX this should really bubble up somehow. */
635 #define LL_RA_MIN ((unsigned long)PTL_MD_MAX_PAGES / 2)
636 #define LL_RA_MAX ((unsigned long)(32 * PTL_MD_MAX_PAGES))
638 /* called with the ras_lock held or from places where it doesn't matter */
639 static void ll_readahead_set(struct ll_readahead_state *ras,
642 ras->ras_next_index = index;
643 if (ras->ras_next_index != ~0UL)
644 ras->ras_next_index++;
645 ras->ras_window = LL_RA_MIN;
646 ras->ras_last = ras->ras_next_index + ras->ras_window;
647 if (ras->ras_last < ras->ras_next_index)
648 ras->ras_last = ~0UL;
649 CDEBUG(D_READA, "ni %lu last %lu win %lu: set %lu\n",
650 ras->ras_next_index, ras->ras_last, ras->ras_window,
654 void ll_readahead_init(struct ll_readahead_state *ras)
656 spin_lock_init(&ras->ras_lock);
657 ll_readahead_set(ras, 0);
660 static void ll_readahead_update(struct ll_readahead_state *ras,
661 unsigned long index, int hit)
663 unsigned long issued_start, new_last;
665 spin_lock(&ras->ras_lock);
667 /* we're interested in noticing the index's relation to the
668 * previously issued read-ahead pages */
669 issued_start = ras->ras_next_index - ras->ras_window - 1;
670 if (issued_start > ras->ras_next_index)
673 CDEBUG(D_READA, "ni %lu last %lu win %lu: %s ind %lu start %lu\n",
674 ras->ras_next_index, ras->ras_last, ras->ras_window,
675 hit ? "hit" : "miss", index, issued_start);
677 index == ras->ras_next_index && index == ras->ras_last + 1) {
678 /* special case the kernel's read-ahead running into the
679 * page just beyond our read-ahead window as an extension
680 * of our read-ahead. sigh. wishing it was easier to
681 * turn off 2.4's read-ahead. */
682 ras->ras_window = min(LL_RA_MAX, ras->ras_window + 1);
684 ras->ras_next_index = index + 1;
685 ras->ras_last = index;
687 (index > issued_start || ras->ras_next_index >= index)) {
688 /* deal with a miss way out of the window. we interpret
689 * this as a seek and restart the window */
690 ll_readahead_set(ras, index);
693 issued_start <= index && index < ras->ras_next_index) {
694 /* a miss inside the window? surely its memory pressure
695 * evicting our read pages before the app can see them.
696 * we shrink the window aggressively */
697 unsigned long old_window = ras->ras_window;
699 ras->ras_window = max(ras->ras_window / 2, LL_RA_MIN);
700 ras->ras_last -= old_window - ras->ras_window;
701 if (ras->ras_next_index > ras->ras_last)
702 ras->ras_next_index = ras->ras_last + 1;
703 CDEBUG(D_READA, "ni %lu last %lu win %lu: miss inside\n",
704 ras->ras_next_index, ras->ras_last, ras->ras_window);
707 issued_start <= index && index < ras->ras_next_index) {
708 /* a hit inside the window. grow the window by twice the
709 * number of pages that are satisified within the window. */
710 ras->ras_window = min(LL_RA_MAX, ras->ras_window + 2);
712 /* we want the next readahead pass to issue a windows worth
713 * beyond where the app currently is */
714 new_last = index + ras->ras_window;
715 if (new_last > ras->ras_last)
716 ras->ras_last = new_last;
718 CDEBUG(D_READA, "ni %lu last %lu win %lu: extended window/last\n",
719 ras->ras_next_index, ras->ras_last, ras->ras_window);
722 spin_unlock(&ras->ras_lock);
726 * for now we do our readpage the same on both 2.4 and 2.5. The kernel's
727 * read-ahead assumes it is valid to issue readpage all the way up to
728 * i_size, but our dlm locks make that not the case. We disable the
729 * kernel's read-ahead and do our own by walking ahead in the page cache
730 * checking for dlm lock coverage. the main difference between 2.4 and
731 * 2.6 is how read-ahead gets batched and issued, but we're using our own,
732 * so they look the same.
734 int ll_readpage(struct file *filp, struct page *page)
736 struct ll_file_data *fd = filp->private_data;
737 struct inode *inode = page->mapping->host;
738 struct obd_export *exp;
740 struct ll_async_page *llap;
743 LASSERT(PageLocked(page));
744 LASSERT(!PageUptodate(page));
745 CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p),offset="LPX64"\n",
746 inode->i_ino, inode->i_generation, inode,
747 (((obd_off)page->index) << PAGE_SHIFT));
748 LASSERT(atomic_read(&filp->f_dentry->d_inode->i_count) > 0);
750 exp = ll_i2obdexp(inode);
752 GOTO(out, rc = -EINVAL);
754 llap = llap_from_page(page);
756 GOTO(out, rc = PTR_ERR(llap));
758 if (llap->llap_defer_uptodate) {
759 ll_readahead_update(&fd->fd_ras, page->index, 1);
760 LL_CDEBUG_PAGE(page, "marking uptodate from defer\n");
761 SetPageUptodate(page);
762 ll_readahead(&fd->fd_ras, exp, page->mapping);
767 ll_readahead_update(&fd->fd_ras, page->index, 0);
769 rc = ll_page_matches(page);
774 static unsigned long next_print;
775 CDEBUG(D_INODE, "didn't match a lock");
776 if (time_after(jiffies, next_print)) {
777 next_print = jiffies + 30 * HZ;
778 CERROR("not covered by a lock (mmap?). check debug "
783 rc = ll_issue_page_read(exp, llap, 0);
785 LL_CDEBUG_PAGE(page, "queued readpage\n");
786 if ((ll_i2sbi(inode)->ll_flags & LL_SBI_READAHEAD))
787 ll_readahead(&fd->fd_ras, exp, page->mapping);
795 /* this is for read pages. we issue them as ready but not urgent. when
796 * someone waits on them we fire them off, hopefully merged with adjacent
797 * reads that were queued by the kernel's read-ahead. */
798 int ll_sync_page(struct page *page)
800 struct obd_export *exp;
801 struct ll_async_page *llap;
805 /* we're abusing PagePrivate to signify that a queued read should
806 * be issued once someone goes to lock it. it is cleared by
807 * canceling the read-ahead page before discarding and by issuing
809 if (!PagePrivate(page))
811 ClearPagePrivate(page);
813 /* careful to only deref page->mapping after checking PagePrivate */
814 exp = ll_i2obdexp(page->mapping->host);
818 llap = llap_from_page(page);
820 RETURN(PTR_ERR(llap));
822 LL_CDEBUG_PAGE(page, "setting ready|urgent\n");
824 rc = obd_set_async_flags(exp, ll_i2info(page->mapping->host)->lli_smd,
825 NULL, llap->llap_cookie,
826 ASYNC_READY|ASYNC_URGENT);