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 --- mm/page_io.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'mm/page_io.c') diff --git a/mm/page_io.c b/mm/page_io.c index 520baa4b04d7..338ce68942a0 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -43,12 +43,11 @@ static struct bio *get_swap_bio(gfp_t gfp_flags, return bio; } -void end_swap_bio_write(struct bio *bio, int err) +void end_swap_bio_write(struct bio *bio) { - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct page *page = bio->bi_io_vec[0].bv_page; - if (!uptodate) { + if (bio->bi_error) { SetPageError(page); /* * We failed to write the page out to swap-space. @@ -69,12 +68,11 @@ void end_swap_bio_write(struct bio *bio, int err) bio_put(bio); } -static void end_swap_bio_read(struct bio *bio, int err) +static void end_swap_bio_read(struct bio *bio) { - const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct page *page = bio->bi_io_vec[0].bv_page; - if (!uptodate) { + if (bio->bi_error) { SetPageError(page); ClearPageUptodate(page); printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n", @@ -254,7 +252,7 @@ static sector_t swap_page_sector(struct page *page) } int __swap_writepage(struct page *page, struct writeback_control *wbc, - void (*end_write_func)(struct bio *, int)) + bio_end_io_t end_write_func) { struct bio *bio; int ret, rw = WRITE; -- cgit v1.2.3 From 6cf66b4caf9c71f64a5486cadbd71ab58d0d4307 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 22 Dec 2014 12:48:42 +0100 Subject: fs: use helper bio_add_page() instead of open coding on bi_io_vec Call pre-defined helper bio_add_page() instead of open coding for iterating through bi_io_vec[]. Doing that, it's possible to make some parts in filesystems and mm/page_io.c simpler than before. Acked-by: Dave Kleikamp Cc: Christoph Hellwig Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kent Overstreet [dpark: add more description in commit message] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- fs/buffer.c | 7 ++----- fs/jfs/jfs_logmgr.c | 14 ++++---------- mm/page_io.c | 8 +++----- 3 files changed, 9 insertions(+), 20 deletions(-) (limited to 'mm/page_io.c') diff --git a/fs/buffer.c b/fs/buffer.c index 7887bb466368..82283abb2795 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3046,12 +3046,9 @@ static int submit_bh_wbc(int rw, struct buffer_head *bh, bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; - bio->bi_io_vec[0].bv_page = bh->b_page; - bio->bi_io_vec[0].bv_len = bh->b_size; - bio->bi_io_vec[0].bv_offset = bh_offset(bh); - bio->bi_vcnt = 1; - bio->bi_iter.bi_size = bh->b_size; + bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh)); + BUG_ON(bio->bi_iter.bi_size != bh->b_size); bio->bi_end_io = end_bio_bh_io_sync; bio->bi_private = bh; diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c index d301acfdb80d..a69bdf2a1085 100644 --- a/fs/jfs/jfs_logmgr.c +++ b/fs/jfs/jfs_logmgr.c @@ -1999,12 +1999,9 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp) bio->bi_iter.bi_sector = bp->l_blkno << (log->l2bsize - 9); bio->bi_bdev = log->bdev; - bio->bi_io_vec[0].bv_page = bp->l_page; - bio->bi_io_vec[0].bv_len = LOGPSIZE; - bio->bi_io_vec[0].bv_offset = bp->l_offset; - bio->bi_vcnt = 1; - bio->bi_iter.bi_size = LOGPSIZE; + bio_add_page(bio, bp->l_page, LOGPSIZE, bp->l_offset); + BUG_ON(bio->bi_iter.bi_size != LOGPSIZE); bio->bi_end_io = lbmIODone; bio->bi_private = bp; @@ -2145,12 +2142,9 @@ static void lbmStartIO(struct lbuf * bp) bio = bio_alloc(GFP_NOFS, 1); bio->bi_iter.bi_sector = bp->l_blkno << (log->l2bsize - 9); bio->bi_bdev = log->bdev; - bio->bi_io_vec[0].bv_page = bp->l_page; - bio->bi_io_vec[0].bv_len = LOGPSIZE; - bio->bi_io_vec[0].bv_offset = bp->l_offset; - bio->bi_vcnt = 1; - bio->bi_iter.bi_size = LOGPSIZE; + bio_add_page(bio, bp->l_page, LOGPSIZE, bp->l_offset); + BUG_ON(bio->bi_iter.bi_size != LOGPSIZE); bio->bi_end_io = lbmIODone; bio->bi_private = bp; diff --git a/mm/page_io.c b/mm/page_io.c index 338ce68942a0..b995a5ba5e8f 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -33,12 +33,10 @@ static struct bio *get_swap_bio(gfp_t gfp_flags, if (bio) { bio->bi_iter.bi_sector = map_swap_page(page, &bio->bi_bdev); bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9; - bio->bi_io_vec[0].bv_page = page; - bio->bi_io_vec[0].bv_len = PAGE_SIZE; - bio->bi_io_vec[0].bv_offset = 0; - bio->bi_vcnt = 1; - bio->bi_iter.bi_size = PAGE_SIZE; bio->bi_end_io = end_io; + + bio_add_page(bio, page, PAGE_SIZE, 0); + BUG_ON(bio->bi_iter.bi_size != PAGE_SIZE); } return bio; } -- cgit v1.2.3