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author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2011-04-04 12:53:28 +0900 |
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committer | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2011-05-10 22:21:44 +0900 |
commit | 1cb2d38cb3e59d58e8321a0592e84b5761afb063 (patch) | |
tree | 151e7ffccd72f786a3da511b0f23906961835a22 /fs/nilfs2/segment.c | |
parent | eaae0f37d83bed7ccd0c6d0f52de1de44f92aecc (diff) | |
download | linux-1cb2d38cb3e59d58e8321a0592e84b5761afb063.tar.gz linux-1cb2d38cb3e59d58e8321a0592e84b5761afb063.tar.bz2 linux-1cb2d38cb3e59d58e8321a0592e84b5761afb063.zip |
nilfs2: get rid of private page allocator
Previously, nilfs was cloning pages for mmapped region to freeze their
data and ensure consistency of checksum during writeback cycles. A
private page allocator was used for this page cloning. But, we no
longer need to do that since clear_page_dirty_for_io function sets up
pte so that vm_ops->page_mkwrite function is called right before the
mmapped pages are modified and nilfs_page_mkwrite function can safely
wait for the pages to be written back to disk.
So, this stops making a copy of mmapped pages during writeback, and
eliminates the private page allocation and deallocation functions from
nilfs.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/segment.c')
-rw-r--r-- | fs/nilfs2/segment.c | 153 |
1 files changed, 17 insertions, 136 deletions
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 5deeadda9083..abbfab974700 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -1556,83 +1556,24 @@ static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) return 0; } -static int -nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out) -{ - struct page *clone_page; - struct buffer_head *bh, *head, *bh2; - void *kaddr; - - bh = head = page_buffers(page); - - clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0); - if (unlikely(!clone_page)) - return -ENOMEM; - - bh2 = page_buffers(clone_page); - kaddr = kmap_atomic(page, KM_USER0); - do { - if (list_empty(&bh->b_assoc_buffers)) - continue; - get_bh(bh2); - page_cache_get(clone_page); /* for each bh */ - memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size); - bh2->b_blocknr = bh->b_blocknr; - list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers); - list_add_tail(&bh->b_assoc_buffers, out); - } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head); - kunmap_atomic(kaddr, KM_USER0); - - if (!TestSetPageWriteback(clone_page)) - account_page_writeback(clone_page); - unlock_page(clone_page); - - return 0; -} - -static int nilfs_test_page_to_be_frozen(struct page *page) -{ - struct address_space *mapping = page->mapping; - - if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode)) - return 0; - - if (page_mapped(page)) { - ClearPageChecked(page); - return 1; - } - return PageChecked(page); -} - -static int nilfs_begin_page_io(struct page *page, struct list_head *out) +static void nilfs_begin_page_io(struct page *page) { if (!page || PageWriteback(page)) /* For split b-tree node pages, this function may be called twice. We ignore the 2nd or later calls by this check. */ - return 0; + return; lock_page(page); clear_page_dirty_for_io(page); set_page_writeback(page); unlock_page(page); - - if (nilfs_test_page_to_be_frozen(page)) { - int err = nilfs_copy_replace_page_buffers(page, out); - if (unlikely(err)) - return err; - } - return 0; } -static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci, - struct page **failed_page) +static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) { struct nilfs_segment_buffer *segbuf; struct page *bd_page = NULL, *fs_page = NULL; - struct list_head *list = &sci->sc_copied_buffers; - int err; - *failed_page = NULL; list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { struct buffer_head *bh; @@ -1662,11 +1603,7 @@ static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci, break; } if (bh->b_page != fs_page) { - err = nilfs_begin_page_io(fs_page, list); - if (unlikely(err)) { - *failed_page = fs_page; - goto out; - } + nilfs_begin_page_io(fs_page); fs_page = bh->b_page; } } @@ -1677,11 +1614,7 @@ static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci, set_page_writeback(bd_page); unlock_page(bd_page); } - err = nilfs_begin_page_io(fs_page, list); - if (unlikely(err)) - *failed_page = fs_page; - out: - return err; + nilfs_begin_page_io(fs_page); } static int nilfs_segctor_write(struct nilfs_sc_info *sci, @@ -1694,24 +1627,6 @@ static int nilfs_segctor_write(struct nilfs_sc_info *sci, return ret; } -static void __nilfs_end_page_io(struct page *page, int err) -{ - if (!err) { - if (!nilfs_page_buffers_clean(page)) - __set_page_dirty_nobuffers(page); - ClearPageError(page); - } else { - __set_page_dirty_nobuffers(page); - SetPageError(page); - } - - if (buffer_nilfs_allocated(page_buffers(page))) { - if (TestClearPageWriteback(page)) - dec_zone_page_state(page, NR_WRITEBACK); - } else - end_page_writeback(page); -} - static void nilfs_end_page_io(struct page *page, int err) { if (!page) @@ -1738,40 +1653,19 @@ static void nilfs_end_page_io(struct page *page, int err) return; } - __nilfs_end_page_io(page, err); -} - -static void nilfs_clear_copied_buffers(struct list_head *list, int err) -{ - struct buffer_head *bh, *head; - struct page *page; - - while (!list_empty(list)) { - bh = list_entry(list->next, struct buffer_head, - b_assoc_buffers); - page = bh->b_page; - page_cache_get(page); - head = bh = page_buffers(page); - do { - if (!list_empty(&bh->b_assoc_buffers)) { - list_del_init(&bh->b_assoc_buffers); - if (!err) { - set_buffer_uptodate(bh); - clear_buffer_dirty(bh); - clear_buffer_delay(bh); - clear_buffer_nilfs_volatile(bh); - } - brelse(bh); /* for b_assoc_buffers */ - } - } while ((bh = bh->b_this_page) != head); - - __nilfs_end_page_io(page, err); - page_cache_release(page); + if (!err) { + if (!nilfs_page_buffers_clean(page)) + __set_page_dirty_nobuffers(page); + ClearPageError(page); + } else { + __set_page_dirty_nobuffers(page); + SetPageError(page); } + + end_page_writeback(page); } -static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page, - int err) +static void nilfs_abort_logs(struct list_head *logs, int err) { struct nilfs_segment_buffer *segbuf; struct page *bd_page = NULL, *fs_page = NULL; @@ -1801,8 +1695,6 @@ static void nilfs_abort_logs(struct list_head *logs, struct page *failed_page, } if (bh->b_page != fs_page) { nilfs_end_page_io(fs_page, err); - if (fs_page && fs_page == failed_page) - return; fs_page = bh->b_page; } } @@ -1821,12 +1713,11 @@ static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, list_splice_tail_init(&sci->sc_write_logs, &logs); ret = nilfs_wait_on_logs(&logs); - nilfs_abort_logs(&logs, NULL, ret ? : err); + nilfs_abort_logs(&logs, ret ? : err); list_splice_tail_init(&sci->sc_segbufs, &logs); nilfs_cancel_segusage(&logs, nilfs->ns_sufile); nilfs_free_incomplete_logs(&logs, nilfs); - nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err); if (sci->sc_stage.flags & NILFS_CF_SUFREED) { ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, @@ -1920,8 +1811,6 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) nilfs_end_page_io(fs_page, 0); - nilfs_clear_copied_buffers(&sci->sc_copied_buffers, 0); - nilfs_drop_collected_inodes(&sci->sc_dirty_files); if (nilfs_doing_gc()) @@ -2024,7 +1913,6 @@ static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) { struct the_nilfs *nilfs = sci->sc_super->s_fs_info; - struct page *failed_page; int err; sci->sc_stage.scnt = NILFS_ST_INIT; @@ -2079,11 +1967,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); /* Write partial segments */ - err = nilfs_segctor_prepare_write(sci, &failed_page); - if (err) { - nilfs_abort_logs(&sci->sc_segbufs, failed_page, err); - goto failed_to_write; - } + nilfs_segctor_prepare_write(sci); nilfs_add_checksums_on_logs(&sci->sc_segbufs, nilfs->ns_crc_seed); @@ -2685,7 +2569,6 @@ static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, INIT_LIST_HEAD(&sci->sc_segbufs); INIT_LIST_HEAD(&sci->sc_write_logs); INIT_LIST_HEAD(&sci->sc_gc_inodes); - INIT_LIST_HEAD(&sci->sc_copied_buffers); init_timer(&sci->sc_timer); sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; @@ -2739,8 +2622,6 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) if (flag || !nilfs_segctor_confirm(sci)) nilfs_segctor_write_out(sci); - WARN_ON(!list_empty(&sci->sc_copied_buffers)); - if (!list_empty(&sci->sc_dirty_files)) { nilfs_warning(sci->sc_super, __func__, "dirty file(s) after the final construction\n"); |