From a72132c31d580969a38972aaf925915e861cd342 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 4 Jun 2014 16:07:49 -0700 Subject: brd: add support for rw_page() Signed-off-by: Matthew Wilcox Cc: Dave Chinner Cc: Dheeraj Reddy Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/brd.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/block') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index e73b85cf0756..807d3d5d2fe5 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -360,6 +360,15 @@ out: bio_endio(bio, err); } +static int brd_rw_page(struct block_device *bdev, sector_t sector, + struct page *page, int rw) +{ + struct brd_device *brd = bdev->bd_disk->private_data; + int err = brd_do_bvec(brd, page, PAGE_CACHE_SIZE, 0, rw, sector); + page_endio(page, rw & WRITE, err); + return err; +} + #ifdef CONFIG_BLK_DEV_XIP static int brd_direct_access(struct block_device *bdev, sector_t sector, void **kaddr, unsigned long *pfn) @@ -419,6 +428,7 @@ static int brd_ioctl(struct block_device *bdev, fmode_t mode, static const struct block_device_operations brd_fops = { .owner = THIS_MODULE, + .rw_page = brd_rw_page, .ioctl = brd_ioctl, #ifdef CONFIG_BLK_DEV_XIP .direct_access = brd_direct_access, -- cgit v1.2.3 From 96f8d8e0965ba3d895f4cf63bbb16fd9fca8998b Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 4 Jun 2014 16:07:50 -0700 Subject: brd: return -ENOSPC rather than -ENOMEM on page allocation failure brd is effectively a thinly provisioned device. Thinly provisioned devices return -ENOSPC when they can't write a new block. -ENOMEM is an implementation detail that callers shouldn't know. Signed-off-by: Matthew Wilcox Acked-by: Dave Chinner Cc: Dheeraj Reddy Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/brd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 807d3d5d2fe5..c7d138eca731 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -200,11 +200,11 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n) copy = min_t(size_t, n, PAGE_SIZE - offset); if (!brd_insert_page(brd, sector)) - return -ENOMEM; + return -ENOSPC; if (copy < n) { sector += copy >> SECTOR_SHIFT; if (!brd_insert_page(brd, sector)) - return -ENOMEM; + return -ENOSPC; } return 0; } @@ -384,7 +384,7 @@ static int brd_direct_access(struct block_device *bdev, sector_t sector, return -ERANGE; page = brd_insert_page(brd, sector); if (!page) - return -ENOMEM; + return -ENOSPC; *kaddr = page_address(page); *pfn = page_to_pfn(page); -- cgit v1.2.3 From 38515c73398a4c58059ecf1087e844561b58ee0f Mon Sep 17 00:00:00 2001 From: Weijie Yang Date: Wed, 4 Jun 2014 16:11:06 -0700 Subject: zram: correct offset usage in zram_bio_discard We want to skip the physical block(PAGE_SIZE) which is partially covered by the discard bio, so we check the remaining size and subtract it if there is a need to goto the next physical block. The current offset usage in zram_bio_discard is incorrect, it will cause its upper filesystem breakdown. Consider the following scenario: On some architecture or config, PAGE_SIZE is 64K for example, filesystem is set up on zram disk without PAGE_SIZE aligned, a discard bio leads to a offset = 4K and size=72K, normally, it should not really discard any physical block as it partially cover two physical blocks. However, with the current offset usage, it will discard the second physical block and free its memory, which will cause filesystem breakdown. This patch corrects the offset usage in zram_bio_discard. Signed-off-by: Weijie Yang Cc: Minchan Kim Cc: Nitin Gupta Acked-by: Joonsoo Kim Cc: Sergey Senozhatsky Cc: Bob Liu Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zram_drv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9849b5233bf4..48eccb350180 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -572,10 +572,10 @@ static void zram_bio_discard(struct zram *zram, u32 index, * skipping this logical block is appropriate here. */ if (offset) { - if (n < offset) + if (n <= (PAGE_SIZE - offset)) return; - n -= offset; + n -= (PAGE_SIZE - offset); index++; } -- cgit v1.2.3