From 8077c0d983ab276ec5f2700df56a64d671781905 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 14 Oct 2013 12:14:13 -0400 Subject: bdi: test bdi_init failure There were two places where return value from bdi_init was not tested. Signed-off-by: Mikulas Patocka Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- fs/char_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/char_dev.c b/fs/char_dev.c index afc2bb691780..b9bc05b9513a 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -574,7 +574,8 @@ static struct kobject *base_probe(dev_t dev, int *part, void *data) void __init chrdev_init(void) { cdev_map = kobj_map_init(base_probe, &chrdevs_lock); - bdi_init(&directly_mappable_cdev_bdi); + if (bdi_init(&directly_mappable_cdev_bdi)) + panic("Failed to init directly mappable cdev bdi"); } -- cgit v1.2.3 From 170d800af83f3ab2b5ced0e370a861e023dee22a Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 15 Oct 2013 12:22:29 -0600 Subject: block: Replace __get_cpu_var uses __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to this_cpu_inc(y) Signed-off-by: Christoph Lameter Signed-off-by: Jens Axboe --- block/blk-iopoll.c | 6 +++--- block/blk-softirq.c | 8 ++++---- fs/fscache/object.c | 2 +- 3 files changed, 8 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/block/blk-iopoll.c b/block/blk-iopoll.c index 4b8d9b541112..1855bf51edb0 100644 --- a/block/blk-iopoll.c +++ b/block/blk-iopoll.c @@ -35,7 +35,7 @@ void blk_iopoll_sched(struct blk_iopoll *iop) unsigned long flags; local_irq_save(flags); - list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll)); + list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll)); __raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ); local_irq_restore(flags); } @@ -79,7 +79,7 @@ EXPORT_SYMBOL(blk_iopoll_complete); static void blk_iopoll_softirq(struct softirq_action *h) { - struct list_head *list = &__get_cpu_var(blk_cpu_iopoll); + struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll); int rearm = 0, budget = blk_iopoll_budget; unsigned long start_time = jiffies; @@ -201,7 +201,7 @@ static int blk_iopoll_cpu_notify(struct notifier_block *self, local_irq_disable(); list_splice_init(&per_cpu(blk_cpu_iopoll, cpu), - &__get_cpu_var(blk_cpu_iopoll)); + this_cpu_ptr(&blk_cpu_iopoll)); __raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ); local_irq_enable(); } diff --git a/block/blk-softirq.c b/block/blk-softirq.c index ec9e60636f43..ce4b8bfd3d27 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -23,7 +23,7 @@ static void blk_done_softirq(struct softirq_action *h) struct list_head *cpu_list, local_list; local_irq_disable(); - cpu_list = &__get_cpu_var(blk_cpu_done); + cpu_list = this_cpu_ptr(&blk_cpu_done); list_replace_init(cpu_list, &local_list); local_irq_enable(); @@ -44,7 +44,7 @@ static void trigger_softirq(void *data) struct list_head *list; local_irq_save(flags); - list = &__get_cpu_var(blk_cpu_done); + list = this_cpu_ptr(&blk_cpu_done); list_add_tail(&rq->csd.list, list); if (list->next == &rq->csd.list) @@ -90,7 +90,7 @@ static int blk_cpu_notify(struct notifier_block *self, unsigned long action, local_irq_disable(); list_splice_init(&per_cpu(blk_cpu_done, cpu), - &__get_cpu_var(blk_cpu_done)); + this_cpu_ptr(&blk_cpu_done)); raise_softirq_irqoff(BLOCK_SOFTIRQ); local_irq_enable(); } @@ -135,7 +135,7 @@ void __blk_complete_request(struct request *req) if (ccpu == cpu || shared) { struct list_head *list; do_local: - list = &__get_cpu_var(blk_cpu_done); + list = this_cpu_ptr(&blk_cpu_done); list_add_tail(&req->csd.list, list); /* diff --git a/fs/fscache/object.c b/fs/fscache/object.c index 86d75a60b20c..3b0712213993 100644 --- a/fs/fscache/object.c +++ b/fs/fscache/object.c @@ -796,7 +796,7 @@ void fscache_enqueue_object(struct fscache_object *object) */ bool fscache_object_sleep_till_congested(signed long *timeoutp) { - wait_queue_head_t *cong_wq = &__get_cpu_var(fscache_object_cong_wait); + wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait); DEFINE_WAIT(wait); if (fscache_object_congested()) -- cgit v1.2.3 From 6678d83f18386eb103f8345024e52c5abe61725c Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 7 Aug 2013 11:14:32 -0700 Subject: block: Consolidate duplicated bio_trim() implementations Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on, we should know better than this. Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: Neil Brown Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Signed-off-by: Jens Axboe --- drivers/block/xen-blkfront.c | 53 +------------------------------------------- drivers/md/md.c | 40 --------------------------------- drivers/md/md.h | 1 - drivers/md/raid1.c | 10 ++++----- drivers/md/raid10.c | 18 +++++++-------- fs/bio.c | 46 ++++++++++++++++++++++++++++++++++++++ include/linux/bio.h | 1 + 7 files changed, 61 insertions(+), 108 deletions(-) (limited to 'fs') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index a4660bbee8a6..8d53ed293606 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1336,57 +1336,6 @@ static int blkfront_probe(struct xenbus_device *dev, return 0; } -/* - * This is a clone of md_trim_bio, used to split a bio into smaller ones - */ -static void trim_bio(struct bio *bio, int offset, int size) -{ - /* 'bio' is a cloned bio which we need to trim to match - * the given offset and size. - * This requires adjusting bi_sector, bi_size, and bi_io_vec - */ - int i; - struct bio_vec *bvec; - int sofar = 0; - - size <<= 9; - if (offset == 0 && size == bio->bi_size) - return; - - bio->bi_sector += offset; - bio->bi_size = size; - offset <<= 9; - clear_bit(BIO_SEG_VALID, &bio->bi_flags); - - while (bio->bi_idx < bio->bi_vcnt && - bio->bi_io_vec[bio->bi_idx].bv_len <= offset) { - /* remove this whole bio_vec */ - offset -= bio->bi_io_vec[bio->bi_idx].bv_len; - bio->bi_idx++; - } - if (bio->bi_idx < bio->bi_vcnt) { - bio->bi_io_vec[bio->bi_idx].bv_offset += offset; - bio->bi_io_vec[bio->bi_idx].bv_len -= offset; - } - /* avoid any complications with bi_idx being non-zero*/ - if (bio->bi_idx) { - memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx, - (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec)); - bio->bi_vcnt -= bio->bi_idx; - bio->bi_idx = 0; - } - /* Make sure vcnt and last bv are not too big */ - bio_for_each_segment(bvec, bio, i) { - if (sofar + bvec->bv_len > size) - bvec->bv_len = size - sofar; - if (bvec->bv_len == 0) { - bio->bi_vcnt = i; - break; - } - sofar += bvec->bv_len; - } -} - static void split_bio_end(struct bio *bio, int error) { struct split_bio *split_bio = bio->bi_private; @@ -1522,7 +1471,7 @@ static int blkif_recover(struct blkfront_info *info) (unsigned int)(bio->bi_size >> 9) - offset); cloned_bio = bio_clone(bio, GFP_NOIO); BUG_ON(cloned_bio == NULL); - trim_bio(cloned_bio, offset, size); + bio_trim(cloned_bio, offset, size); cloned_bio->bi_private = split_bio; cloned_bio->bi_end_io = split_bio_end; submit_bio(cloned_bio->bi_rw, cloned_bio); diff --git a/drivers/md/md.c b/drivers/md/md.c index 561a65f82e26..752119068d66 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -183,46 +183,6 @@ struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, } EXPORT_SYMBOL_GPL(bio_clone_mddev); -void md_trim_bio(struct bio *bio, int offset, int size) -{ - /* 'bio' is a cloned bio which we need to trim to match - * the given offset and size. - * This requires adjusting bi_sector, bi_size, and bi_io_vec - */ - int i; - struct bio_vec *bvec; - int sofar = 0; - - size <<= 9; - if (offset == 0 && size == bio->bi_size) - return; - - clear_bit(BIO_SEG_VALID, &bio->bi_flags); - - bio_advance(bio, offset << 9); - - bio->bi_size = size; - - /* avoid any complications with bi_idx being non-zero*/ - if (bio->bi_idx) { - memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx, - (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec)); - bio->bi_vcnt -= bio->bi_idx; - bio->bi_idx = 0; - } - /* Make sure vcnt and last bv are not too big */ - bio_for_each_segment(bvec, bio, i) { - if (sofar + bvec->bv_len > size) - bvec->bv_len = size - sofar; - if (bvec->bv_len == 0) { - bio->bi_vcnt = i; - break; - } - sofar += bvec->bv_len; - } -} -EXPORT_SYMBOL_GPL(md_trim_bio); - /* * We have a system wide 'event count' that is incremented * on any 'interesting' event, and readers of /proc/mdstat diff --git a/drivers/md/md.h b/drivers/md/md.h index 608050c43f17..c96456c16700 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -617,7 +617,6 @@ extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, struct mddev *mddev); extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, struct mddev *mddev); -extern void md_trim_bio(struct bio *bio, int offset, int size); extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule); static inline int mddev_check_plugged(struct mddev *mddev) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index aacf6bf352d8..af6681b19776 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1097,8 +1097,8 @@ read_again: r1_bio->read_disk = rdisk; read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector, - max_sectors); + bio_trim(read_bio, r1_bio->sector - bio->bi_sector, + max_sectors); r1_bio->bios[rdisk] = read_bio; @@ -1266,7 +1266,7 @@ read_again: continue; mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors); + bio_trim(mbio, r1_bio->sector - bio->bi_sector, max_sectors); if (first_clone) { /* do behind I/O ? @@ -2126,7 +2126,7 @@ static int narrow_write_error(struct r1bio *r1_bio, int i) wbio->bi_sector = r1_bio->sector; wbio->bi_size = r1_bio->sectors << 9; - md_trim_bio(wbio, sector - r1_bio->sector, sectors); + bio_trim(wbio, sector - r1_bio->sector, sectors); wbio->bi_sector += rdev->data_offset; wbio->bi_bdev = rdev->bdev; if (submit_bio_wait(WRITE, wbio) == 0) @@ -2241,7 +2241,7 @@ read_more: } r1_bio->read_disk = disk; bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); - md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors); + bio_trim(bio, r1_bio->sector - bio->bi_sector, max_sectors); r1_bio->bios[r1_bio->read_disk] = bio; rdev = conf->mirrors[disk].rdev; printk_ratelimited(KERN_ERR diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 73dc8a377522..7c3508abb5e1 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1302,8 +1302,8 @@ read_again: slot = r10_bio->read_slot; read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector, - max_sectors); + bio_trim(read_bio, r10_bio->sector - bio->bi_sector, + max_sectors); r10_bio->devs[slot].bio = read_bio; r10_bio->devs[slot].rdev = rdev; @@ -1510,8 +1510,8 @@ retry_write: if (r10_bio->devs[i].bio) { struct md_rdev *rdev = conf->mirrors[d].rdev; mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(mbio, r10_bio->sector - bio->bi_sector, - max_sectors); + bio_trim(mbio, r10_bio->sector - bio->bi_sector, + max_sectors); r10_bio->devs[i].bio = mbio; mbio->bi_sector = (r10_bio->devs[i].addr+ @@ -1553,8 +1553,8 @@ retry_write: rdev = conf->mirrors[d].rdev; } mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(mbio, r10_bio->sector - bio->bi_sector, - max_sectors); + bio_trim(mbio, r10_bio->sector - bio->bi_sector, + max_sectors); r10_bio->devs[i].repl_bio = mbio; mbio->bi_sector = (r10_bio->devs[i].addr + @@ -2614,7 +2614,7 @@ static int narrow_write_error(struct r10bio *r10_bio, int i) sectors = sect_to_write; /* Write at 'sector' for 'sectors' */ wbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(wbio, sector - bio->bi_sector, sectors); + bio_trim(wbio, sector - bio->bi_sector, sectors); wbio->bi_sector = (r10_bio->devs[i].addr+ choose_data_offset(r10_bio, rdev) + (sector - r10_bio->sector)); @@ -2687,9 +2687,7 @@ read_more: (unsigned long long)r10_bio->sector); bio = bio_clone_mddev(r10_bio->master_bio, GFP_NOIO, mddev); - md_trim_bio(bio, - r10_bio->sector - bio->bi_sector, - max_sectors); + bio_trim(bio, r10_bio->sector - bio->bi_sector, max_sectors); r10_bio->devs[slot].bio = bio; r10_bio->devs[slot].rdev = rdev; bio->bi_sector = r10_bio->devs[slot].addr diff --git a/fs/bio.c b/fs/bio.c index ea5035da4d9a..2bdb4e25ee77 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1804,6 +1804,52 @@ struct bio_pair *bio_split(struct bio *bi, int first_sectors) } EXPORT_SYMBOL(bio_split); +/** + * bio_trim - trim a bio + * @bio: bio to trim + * @offset: number of sectors to trim from the front of @bio + * @size: size we want to trim @bio to, in sectors + */ +void bio_trim(struct bio *bio, int offset, int size) +{ + /* 'bio' is a cloned bio which we need to trim to match + * the given offset and size. + * This requires adjusting bi_sector, bi_size, and bi_io_vec + */ + int i; + struct bio_vec *bvec; + int sofar = 0; + + size <<= 9; + if (offset == 0 && size == bio->bi_size) + return; + + clear_bit(BIO_SEG_VALID, &bio->bi_flags); + + bio_advance(bio, offset << 9); + + bio->bi_size = size; + + /* avoid any complications with bi_idx being non-zero*/ + if (bio->bi_idx) { + memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx, + (bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec)); + bio->bi_vcnt -= bio->bi_idx; + bio->bi_idx = 0; + } + /* Make sure vcnt and last bv are not too big */ + bio_for_each_segment(bvec, bio, i) { + if (sofar + bvec->bv_len > size) + bvec->bv_len = size - sofar; + if (bvec->bv_len == 0) { + bio->bi_vcnt = i; + break; + } + sofar += bvec->bv_len; + } +} +EXPORT_SYMBOL_GPL(bio_trim); + /** * bio_sector_offset - Find hardware sector offset in bio * @bio: bio to inspect diff --git a/include/linux/bio.h b/include/linux/bio.h index ec48bac5b039..162036aca741 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -218,6 +218,7 @@ struct bio_pair { }; extern struct bio_pair *bio_split(struct bio *bi, int first_sectors); extern void bio_pair_release(struct bio_pair *dbio); +extern void bio_trim(struct bio *bio, int offset, int size); extern struct bio_set *bioset_create(unsigned int, unsigned int); extern void bioset_free(struct bio_set *); -- cgit v1.2.3