From 4246a0b63bd8f56a1469b12eafeb875b1041a451 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 20 Jul 2015 15:29:37 +0200 Subject: block: add a bi_error field to struct bio Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe --- fs/btrfs/compression.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'fs/btrfs/compression.c') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index ce62324c78e7..302266ec2cdb 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -152,7 +152,7 @@ fail: * The compressed pages are freed here, and it must be run * in process context */ -static void end_compressed_bio_read(struct bio *bio, int err) +static void end_compressed_bio_read(struct bio *bio) { struct compressed_bio *cb = bio->bi_private; struct inode *inode; @@ -160,7 +160,7 @@ static void end_compressed_bio_read(struct bio *bio, int err) unsigned long index; int ret; - if (err) + if (bio->bi_error) cb->errors = 1; /* if there are more bios still pending for this compressed @@ -210,7 +210,7 @@ csum_failed: bio_for_each_segment_all(bvec, cb->orig_bio, i) SetPageChecked(bvec->bv_page); - bio_endio(cb->orig_bio, 0); + bio_endio(cb->orig_bio); } /* finally free the cb struct */ @@ -266,7 +266,7 @@ static noinline void end_compressed_writeback(struct inode *inode, * This also calls the writeback end hooks for the file pages so that * metadata and checksums can be updated in the file. */ -static void end_compressed_bio_write(struct bio *bio, int err) +static void end_compressed_bio_write(struct bio *bio) { struct extent_io_tree *tree; struct compressed_bio *cb = bio->bi_private; @@ -274,7 +274,7 @@ static void end_compressed_bio_write(struct bio *bio, int err) struct page *page; unsigned long index; - if (err) + if (bio->bi_error) cb->errors = 1; /* if there are more bios still pending for this compressed @@ -293,7 +293,7 @@ static void end_compressed_bio_write(struct bio *bio, int err) cb->start, cb->start + cb->len - 1, NULL, - err ? 0 : 1); + bio->bi_error ? 0 : 1); cb->compressed_pages[0]->mapping = NULL; end_compressed_writeback(inode, cb); @@ -697,8 +697,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, ret = btrfs_map_bio(root, READ, comp_bio, mirror_num, 0); - if (ret) - bio_endio(comp_bio, ret); + if (ret) { + bio->bi_error = ret; + bio_endio(comp_bio); + } bio_put(comp_bio); @@ -724,8 +726,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, } ret = btrfs_map_bio(root, READ, comp_bio, mirror_num, 0); - if (ret) - bio_endio(comp_bio, ret); + if (ret) { + bio->bi_error = ret; + bio_endio(comp_bio); + } bio_put(comp_bio); return 0; -- cgit v1.2.3 From b54ffb73cadcdcff9cc1ae0e11f502407e3e2e4c Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 19 May 2015 14:31:01 +0200 Subject: block: remove bio_get_nr_vecs() We can always fill up the bio now, no need to estimate the possible size based on queue parameters. Acked-by: Steven Whitehouse Signed-off-by: Kent Overstreet [hch: rebased and wrote a changelog] Signed-off-by: Christoph Hellwig Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- fs/btrfs/compression.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/btrfs/compression.c') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 302266ec2cdb..57ee8ca29b06 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -97,10 +97,7 @@ static inline int compressed_bio_size(struct btrfs_root *root, static struct bio *compressed_bio_alloc(struct block_device *bdev, u64 first_byte, gfp_t gfp_flags) { - int nr_vecs; - - nr_vecs = bio_get_nr_vecs(bdev); - return btrfs_bio_alloc(bdev, first_byte >> 9, nr_vecs, gfp_flags); + return btrfs_bio_alloc(bdev, first_byte >> 9, BIO_MAX_PAGES, gfp_flags); } static int check_compressed_csum(struct inode *inode, -- cgit v1.2.3