From patchwork Wed Dec 10 13:14:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Rajendra X-Patchwork-Id: 5468961 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 94B0B9F2E8 for ; Wed, 10 Dec 2014 13:14:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 56FA32015A for ; Wed, 10 Dec 2014 13:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7FFD20115 for ; Wed, 10 Dec 2014 13:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755824AbaLJNOo (ORCPT ); Wed, 10 Dec 2014 08:14:44 -0500 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:51371 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755443AbaLJNOl (ORCPT ); Wed, 10 Dec 2014 08:14:41 -0500 Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Date: Wed, 10 Dec 2014 18:44:03 +0530 Message-Id: <1418217261-17273-2-git-send-email-chandan@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1418217261-17273-1-git-send-email-chandan@linux.vnet.ibm.com> References: <1418217261-17273-1-git-send-email-chandan@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14121013-0033-0000-0000-000003435EF6 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Based on original patch from Aneesh Kumar K.V For the subpagesize-blocksize scenario, a page can contain multiple blocks. This patch handles this case. This patch adds the new EXTENT_READ_IO extent state bit to reliably unlock pages in readpage's end bio function. Signed-off-by: Chandan Rajendra --- fs/btrfs/extent_io.c | 182 ++++++++++++++++++++++++--------------------------- fs/btrfs/extent_io.h | 5 +- 2 files changed, 89 insertions(+), 98 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a389820..c98dfd8 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1951,14 +1951,23 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, * helper function to set a given page up to date if all the * extents in the tree for that page are up to date */ -static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) +static void check_page_uptodate(struct extent_io_tree *tree, struct page *page, + struct extent_state *cached) { u64 start = page_offset(page); u64 end = start + PAGE_CACHE_SIZE - 1; - if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL)) + if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, cached)) SetPageUptodate(page); } +static int page_read_complete(struct extent_io_tree *tree, struct page *page) +{ + u64 start = page_offset(page); + u64 end = start + PAGE_CACHE_SIZE - 1; + + return !test_range_bit(tree, start, end, EXTENT_READ_IO, 0, NULL); +} + /* * When IO fails, either with EIO or csum verification fails, we * try other mirrors that might have a good copy of the data. This @@ -2275,7 +2284,9 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, * a) deliver good data to the caller * b) correct the bad sectors on disk */ - if (failed_bio->bi_vcnt > 1) { + if ((failed_bio->bi_vcnt > 1) + || (failed_bio->bi_io_vec->bv_len + > BTRFS_I(inode)->root->sectorsize)) { /* * to fulfill b), we need to know the exact failing sectors, as * we don't want to rewrite any more than the failed ones. thus, @@ -2422,18 +2433,6 @@ static void end_bio_extent_writepage(struct bio *bio, int err) bio_put(bio); } -static void -endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len, - int uptodate) -{ - struct extent_state *cached = NULL; - u64 end = start + len - 1; - - if (uptodate && tree->track_uptodate) - set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC); - unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC); -} - /* * after a readpage IO is done, we need to: * clear the uptodate bits on error @@ -2450,14 +2449,15 @@ static void end_bio_extent_readpage(struct bio *bio, int err) struct bio_vec *bvec; int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + struct extent_state *cached = NULL; struct extent_io_tree *tree; + unsigned long flags; u64 offset = 0; u64 start; u64 end; - u64 len; - u64 extent_start = 0; - u64 extent_len = 0; + int nr_sectors; int mirror; + int unlock; int ret; int i; @@ -2467,54 +2467,31 @@ static void end_bio_extent_readpage(struct bio *bio, int err) bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; struct inode *inode = page->mapping->host; + struct btrfs_root *root = BTRFS_I(inode)->root; pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, " "mirror=%lu\n", (u64)bio->bi_iter.bi_sector, err, io_bio->mirror_num); tree = &BTRFS_I(inode)->io_tree; - /* We always issue full-page reads, but if some block - * in a page fails to read, blk_update_request() will - * advance bv_offset and adjust bv_len to compensate. - * Print a warning for nonzero offsets, and an error - * if they don't add up to a full page. */ - if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE) { - if (bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE) - btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info, - "partial page read in btrfs with offset %u and length %u", - bvec->bv_offset, bvec->bv_len); - else - btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info, - "incomplete page read in btrfs with offset %u and " - "length %u", - bvec->bv_offset, bvec->bv_len); - } - - start = page_offset(page); - end = start + bvec->bv_offset + bvec->bv_len - 1; - len = bvec->bv_len; - + start = page_offset(page) + bvec->bv_offset; + end = start + bvec->bv_len - 1; + nr_sectors = bvec->bv_len >> inode->i_sb->s_blocksize_bits; mirror = io_bio->mirror_num; - if (likely(uptodate && tree->ops && - tree->ops->readpage_end_io_hook)) { + +next_block: + if (likely(uptodate)) { ret = tree->ops->readpage_end_io_hook(io_bio, offset, - page, start, end, - mirror); + page, start, + start + root->sectorsize - 1, + mirror); if (ret) uptodate = 0; else clean_io_failure(start, page); } - if (likely(uptodate)) - goto readpage_ok; - - if (tree->ops && tree->ops->readpage_io_failed_hook) { - ret = tree->ops->readpage_io_failed_hook(page, mirror); - if (!ret && !err && - test_bit(BIO_UPTODATE, &bio->bi_flags)) - uptodate = 1; - } else { + if (!uptodate) { /* * The generic bio_readpage_error handles errors the * following way: If possible, new read requests are @@ -2525,60 +2502,64 @@ static void end_bio_extent_readpage(struct bio *bio, int err) * can't handle the error it will return -EIO and we * remain responsible for that page. */ - ret = bio_readpage_error(bio, offset, page, start, end, - mirror); + ret = bio_readpage_error(bio, offset, page, + start, start + root->sectorsize - 1, + mirror); if (ret == 0) { - uptodate = - test_bit(BIO_UPTODATE, &bio->bi_flags); + uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); if (err) uptodate = 0; - continue; + offset += root->sectorsize; + if (--nr_sectors) { + start += root->sectorsize; + goto next_block; + } else { + continue; + } } } -readpage_ok: - if (likely(uptodate)) { - loff_t i_size = i_size_read(inode); - pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; - unsigned offset; - - /* Zero out the end if this page straddles i_size */ - offset = i_size & (PAGE_CACHE_SIZE-1); - if (page->index == end_index && offset) - zero_user_segment(page, offset, PAGE_CACHE_SIZE); - SetPageUptodate(page); + + if (uptodate) { + set_extent_uptodate(tree, start, + start + root->sectorsize - 1, + &cached, GFP_ATOMIC); + check_page_uptodate(tree, page, cached); } else { ClearPageUptodate(page); SetPageError(page); } - unlock_page(page); - offset += len; - - if (unlikely(!uptodate)) { - if (extent_len) { - endio_readpage_release_extent(tree, - extent_start, - extent_len, 1); - extent_start = 0; - extent_len = 0; - } - endio_readpage_release_extent(tree, start, - end - start + 1, 0); - } else if (!extent_len) { - extent_start = start; - extent_len = end + 1 - start; - } else if (extent_start + extent_len == start) { - extent_len += end + 1 - start; - } else { - endio_readpage_release_extent(tree, extent_start, - extent_len, uptodate); - extent_start = start; - extent_len = end + 1 - start; + + offset += root->sectorsize; + + if (--nr_sectors) { + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_READ_IO, 0, 0, &cached, GFP_ATOMIC); + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_LOCKED, 1, 0, &cached, GFP_ATOMIC); + start += root->sectorsize; + goto next_block; } + + WARN_ON(!PagePrivate(page)); + + local_irq_save(flags); + bit_spin_lock(EXTENT_PAGE_UPTODATE_LOCK, &page->private); + + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_READ_IO, 0, 0, &cached, GFP_ATOMIC); + + unlock = page_read_complete(tree, page); + + bit_spin_unlock(EXTENT_PAGE_UPTODATE_LOCK, &page->private); + local_irq_restore(flags); + + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_LOCKED, 1, 0, &cached, GFP_ATOMIC); + + if (unlock) + unlock_page(page); } - if (extent_len) - endio_readpage_release_extent(tree, extent_start, extent_len, - uptodate); if (io_bio->end_io) io_bio->end_io(io_bio, err); bio_put(bio); @@ -2799,6 +2780,7 @@ static int __do_readpage(struct extent_io_tree *tree, unsigned long *bio_flags, int rw) { struct inode *inode = page->mapping->host; + struct extent_state *cached = NULL; u64 start = page_offset(page); u64 page_end = start + PAGE_CACHE_SIZE - 1; u64 end; @@ -2918,7 +2900,7 @@ static int __do_readpage(struct extent_io_tree *tree, /* the get_extent function already copied into the page */ if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1, NULL)) { - check_page_uptodate(tree, page); + check_page_uptodate(tree, page, NULL); if (!parent_locked) unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; @@ -2938,6 +2920,10 @@ static int __do_readpage(struct extent_io_tree *tree, } pnr -= page->index; + + set_extent_bit(tree, cur, cur + iosize - 1, EXTENT_READ_IO, + NULL, &cached, GFP_NOFS); + ret = submit_extent_page(rw, tree, page, sector, disk_io_size, pg_offset, bdev, bio, pnr, @@ -2949,8 +2935,12 @@ static int __do_readpage(struct extent_io_tree *tree, *bio_flags = this_bio_flag; } else { SetPageError(page); + clear_extent_bit(tree, cur, cur + iosize - 1, + EXTENT_READ_IO, 0, 0, &cached, + GFP_NOFS); if (!parent_locked) - unlock_extent(tree, cur, cur + iosize - 1); + unlock_extent_cached(tree, cur, cur + iosize - 1, + &cached, GFP_NOFS); } cur = cur + iosize; pg_offset += iosize; diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index ccc264e..4d019c0 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -20,6 +20,7 @@ #define EXTENT_NEED_WAIT (1 << 13) #define EXTENT_DAMAGED (1 << 14) #define EXTENT_NORESERVE (1 << 15) +#define EXTENT_READ_IO (1 << 16) #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK) #define EXTENT_CTLBITS (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC) @@ -56,8 +57,8 @@ * page->private values. Every page that is controlled by the extent * map has page->private set to one. */ -#define EXTENT_PAGE_PRIVATE 1 -#define EXTENT_PAGE_PRIVATE_FIRST_PAGE 3 +#define EXTENT_PAGE_PRIVATE (1 << 0) +#define EXTENT_PAGE_UPTODATE_LOCK (1 << 1) struct extent_state; struct btrfs_root;