From bcb21c8cc9947286211327d663ace69f07d37a76 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 17 Aug 2020 18:01:30 +0800 Subject: block: loop: set discard granularity and alignment for block device backed loop In case of block device backend, if the backend supports write zeros, the loop device will set queue flag of QUEUE_FLAG_DISCARD. However, limits.discard_granularity isn't setup, and this way is wrong, see the following description in Documentation/ABI/testing/sysfs-block: A discard_granularity of 0 means that the device does not support discard functionality. Especially 9b15d109a6b2 ("block: improve discard bio alignment in __blkdev_issue_discard()") starts to take q->limits.discard_granularity for computing max discard sectors. And zero discard granularity may cause kernel oops, or fail discard request even though the loop queue claims discard support via QUEUE_FLAG_DISCARD. Fix the issue by setup discard granularity and alignment. Fixes: c52abf563049 ("loop: Better discard support for block devices") Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Acked-by: Coly Li Cc: Hannes Reinecke Cc: Xiao Ni Cc: Martin K. Petersen Cc: Evan Green Cc: Gwendal Grignou Cc: Chaitanya Kulkarni Cc: Andrzej Pietrasiewicz Cc: Christoph Hellwig Cc: Signed-off-by: Jens Axboe --- drivers/block/loop.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 2f137d6ce169..3d7a1901bf28 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -878,6 +878,7 @@ static void loop_config_discard(struct loop_device *lo) struct file *file = lo->lo_backing_file; struct inode *inode = file->f_mapping->host; struct request_queue *q = lo->lo_queue; + u32 granularity, max_discard_sectors; /* * If the backing device is a block device, mirror its zeroing @@ -890,11 +891,10 @@ static void loop_config_discard(struct loop_device *lo) struct request_queue *backingq; backingq = bdev_get_queue(inode->i_bdev); - blk_queue_max_discard_sectors(q, - backingq->limits.max_write_zeroes_sectors); - blk_queue_max_write_zeroes_sectors(q, - backingq->limits.max_write_zeroes_sectors); + max_discard_sectors = backingq->limits.max_write_zeroes_sectors; + granularity = backingq->limits.discard_granularity ?: + queue_physical_block_size(backingq); /* * We use punch hole to reclaim the free space used by the @@ -903,23 +903,26 @@ static void loop_config_discard(struct loop_device *lo) * useful information. */ } else if (!file->f_op->fallocate || lo->lo_encrypt_key_size) { - q->limits.discard_granularity = 0; - q->limits.discard_alignment = 0; - blk_queue_max_discard_sectors(q, 0); - blk_queue_max_write_zeroes_sectors(q, 0); + max_discard_sectors = 0; + granularity = 0; } else { - q->limits.discard_granularity = inode->i_sb->s_blocksize; - q->limits.discard_alignment = 0; - - blk_queue_max_discard_sectors(q, UINT_MAX >> 9); - blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9); + max_discard_sectors = UINT_MAX >> 9; + granularity = inode->i_sb->s_blocksize; } - if (q->limits.max_write_zeroes_sectors) + if (max_discard_sectors) { + q->limits.discard_granularity = granularity; + blk_queue_max_discard_sectors(q, max_discard_sectors); + blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); - else + } else { + q->limits.discard_granularity = 0; + blk_queue_max_discard_sectors(q, 0); + blk_queue_max_write_zeroes_sectors(q, 0); blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); + } + q->limits.discard_alignment = 0; } static void loop_unprepare_queue(struct loop_device *lo) -- cgit v1.2.3 From df561f6688fef775baa341a0f5d960becd248b11 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Sun, 23 Aug 2020 17:36:59 -0500 Subject: treewide: Use fallthrough pseudo-keyword Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva --- drivers/block/loop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 2f137d6ce169..33cc6558f9d2 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1719,7 +1719,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, case LOOP_SET_BLOCK_SIZE: if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) return -EPERM; - /* Fall through */ + fallthrough; default: err = lo_simple_ioctl(lo, cmd, arg); break; @@ -1867,7 +1867,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, case LOOP_SET_STATUS64: case LOOP_CONFIGURE: arg = (unsigned long) compat_ptr(arg); - /* fall through */ + fallthrough; case LOOP_SET_FD: case LOOP_CHANGE_FD: case LOOP_SET_BLOCK_SIZE: -- cgit v1.2.3 From 79e5dc59e2974a48764269fa9ff544ae8ffe3338 Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Tue, 25 Aug 2020 09:18:29 +0200 Subject: loop: Set correct device size when using LOOP_CONFIGURE The device size calculation was done before processing the loop configuration, which meant that the we set the size on the underlying block device incorrectly in case lo_offset/lo_sizelimit were set in the configuration. Delay computing the size until we've setup the device parameters correctly. Fixes: 3448914e8cc5("loop: Add LOOP_CONFIGURE ioctl") Reported-by: Lennart Poettering Tested-by: Yang Xu Signed-off-by: Martijn Coenen Signed-off-by: Jens Axboe --- drivers/block/loop.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/block/loop.c') diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 3d7a1901bf28..03ce01c64874 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1114,8 +1114,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, mapping = file->f_mapping; inode = mapping->host; - size = get_loop_size(lo, file); - if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { error = -EINVAL; goto out_unlock; @@ -1165,6 +1163,8 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, loop_update_rotational(lo); loop_update_dio(lo); loop_sysfs_init(lo); + + size = get_loop_size(lo, file); loop_set_size(lo, size); set_blocksize(bdev, S_ISBLK(inode->i_mode) ? -- cgit v1.2.3