[PATCH] Btrfs: handle bio_add_page failure gracefully in scrub
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From: Arne Jansen <hidden>
Date: 2011-11-11 08:12:21
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Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
Currently scrub fails with ENOMEM when bio_add_page fails. Unfortunately dm based targets accept only one page per bio, thus making scrub always fails. This patch just submits the current bio when an error is encountered and starts a new one. Signed-off-by: Arne Jansen <redacted> --- fs/btrfs/scrub.c | 64 ++++++++++++++++++++++++----------------------------- 1 files changed, 29 insertions(+), 35 deletions(-)
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index ed11d38..f4190f2 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c@@ -944,50 +944,18 @@ static int scrub_checksum_super(struct scrub_bio *sbio, void *buffer) static int scrub_submit(struct scrub_dev *sdev) { struct scrub_bio *sbio; - struct bio *bio; - int i; if (sdev->curr == -1) return 0; sbio = sdev->bios[sdev->curr]; - - bio = bio_alloc(GFP_NOFS, sbio->count); - if (!bio) - goto nomem; - - bio->bi_private = sbio; - bio->bi_end_io = scrub_bio_end_io; - bio->bi_bdev = sdev->dev->bdev; - bio->bi_sector = sbio->physical >> 9; - - for (i = 0; i < sbio->count; ++i) { - struct page *page; - int ret; - - page = alloc_page(GFP_NOFS); - if (!page) - goto nomem; - - ret = bio_add_page(bio, page, PAGE_SIZE, 0); - if (!ret) { - __free_page(page); - goto nomem; - } - } - sbio->err = 0; sdev->curr = -1; atomic_inc(&sdev->in_flight); - submit_bio(READ, bio); + submit_bio(READ, sbio->bio); return 0; - -nomem: - scrub_free_bio(bio); - - return -ENOMEM; } static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
@@ -995,6 +963,8 @@ static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len, u8 *csum, int force) { struct scrub_bio *sbio; + struct page *page; + int ret; again: /*
@@ -1015,12 +985,22 @@ again: } sbio = sdev->bios[sdev->curr]; if (sbio->count == 0) { + struct bio *bio; + sbio->physical = physical; sbio->logical = logical; + bio = bio_alloc(GFP_NOFS, SCRUB_PAGES_PER_BIO); + if (!bio) + return -ENOMEM; + + bio->bi_private = sbio; + bio->bi_end_io = scrub_bio_end_io; + bio->bi_bdev = sdev->dev->bdev; + bio->bi_sector = sbio->physical >> 9; + sbio->err = 0; + sbio->bio = bio; } else if (sbio->physical + sbio->count * PAGE_SIZE != physical || sbio->logical + sbio->count * PAGE_SIZE != logical) { - int ret; - ret = scrub_submit(sdev); if (ret) return ret;
@@ -1030,6 +1010,20 @@ again: sbio->spag[sbio->count].generation = gen; sbio->spag[sbio->count].have_csum = 0; sbio->spag[sbio->count].mirror_num = mirror_num; + + page = alloc_page(GFP_NOFS); + if (!page) + return -ENOMEM; + + ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0); + if (!ret) { + __free_page(page); + ret = scrub_submit(sdev); + if (ret) + return ret; + goto again; + } + if (csum) { sbio->spag[sbio->count].have_csum = 1; memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);
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1.7.3.4