From 593a9e7b34fa62d703b473ae923a9681556cdf74 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 7 Feb 2012 12:03:37 -0600 Subject: [PATCH] rbd: small changes Here is another set of small code tidy-ups: - Define SECTOR_SHIFT and SECTOR_SIZE, and use these symbolic names throughout. Tell the blk_queue system our physical block size, in the (unlikely) event we want to use something other than the default. - Delete the definition of struct rbd_info, which is never used. - Move the definition of dev_to_rbd() down in its source file, just above where it gets first used, and change its name to dev_to_rbd_dev(). - Replace an open-coded operation in rbd_dev_release() to use dev_to_rbd_dev() instead. - Calculate the segment size for a given rbd_device just once in rbd_init_disk(). - Use the '%zd' conversion specifier in rbd_snap_size_show(), since the value formatted is a size_t. - Switch to the '%llu' conversion specifier in rbd_snap_id_show(). since the value formatted is unsigned. Signed-off-by: Alex Elder --- drivers/block/rbd.c | 85 ++++++++++++++++++++++++--------------- drivers/block/rbd_types.h | 4 -- 2 files changed, 52 insertions(+), 37 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index a42b28e7f3fa..568fa5b1206b 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -41,6 +41,15 @@ #include "rbd_types.h" +/* + * The basic unit of block I/O is a sector. It is interpreted in a + * number of contexts in Linux (blk, bio, genhd), but the default is + * universally 512 bytes. These symbols are just slightly more + * meaningful than the bare numbers they represent. + */ +#define SECTOR_SHIFT 9 +#define SECTOR_SIZE (1ULL << SECTOR_SHIFT) + #define RBD_DRV_NAME "rbd" #define RBD_DRV_NAME_LONG "rbd (rados block device)" @@ -221,11 +230,6 @@ static struct device rbd_root_dev = { }; -static struct rbd_device *dev_to_rbd(struct device *dev) -{ - return container_of(dev, struct rbd_device, dev); -} - static struct device *rbd_get_dev(struct rbd_device *rbd_dev) { return get_device(&rbd_dev->dev); @@ -743,7 +747,7 @@ static struct bio *bio_chain_clone(struct bio **old, struct bio **next, /* split the bio. We'll release it either in the next call, or it will have to be released outside */ - bp = bio_split(old_chain, (len - total) / 512ULL); + bp = bio_split(old_chain, (len - total) / SECTOR_SIZE); if (!bp) goto err_out; @@ -1471,7 +1475,7 @@ static void rbd_rq_fn(struct request_queue *q) do_write = (rq_data_dir(rq) == WRITE); size = blk_rq_bytes(rq); - ofs = blk_rq_pos(rq) * 512ULL; + ofs = blk_rq_pos(rq) * SECTOR_SIZE; rq_bio = rq->bio; if (do_write && rbd_dev->read_only) { __blk_end_request_all(rq, -EROFS); @@ -1482,7 +1486,7 @@ static void rbd_rq_fn(struct request_queue *q) dout("%s 0x%x bytes at 0x%llx\n", do_write ? "write" : "read", - size, blk_rq_pos(rq) * 512ULL); + size, blk_rq_pos(rq) * SECTOR_SIZE); num_segs = rbd_get_num_segments(&rbd_dev->header, ofs, size); coll = rbd_alloc_coll(num_segs); @@ -1547,13 +1551,17 @@ static int rbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd, struct bio_vec *bvec) { struct rbd_device *rbd_dev = q->queuedata; - unsigned int chunk_sectors = 1 << (rbd_dev->header.obj_order - 9); - sector_t sector = bmd->bi_sector + get_start_sect(bmd->bi_bdev); - unsigned int bio_sectors = bmd->bi_size >> 9; + unsigned int chunk_sectors; + sector_t sector; + unsigned int bio_sectors; int max; + chunk_sectors = 1 << (rbd_dev->header.obj_order - SECTOR_SHIFT); + sector = bmd->bi_sector + get_start_sect(bmd->bi_bdev); + bio_sectors = bmd->bi_size >> SECTOR_SHIFT; + max = (chunk_sectors - ((sector & (chunk_sectors - 1)) - + bio_sectors)) << 9; + + bio_sectors)) << SECTOR_SHIFT; if (max < 0) max = 0; /* bio_add cannot handle a negative return */ if (max <= bvec->bv_len && bio_sectors == 0) @@ -1708,7 +1716,7 @@ static int __rbd_update_snaps(struct rbd_device *rbd_dev) return ret; /* resized? */ - set_capacity(rbd_dev->disk, h.image_size / 512ULL); + set_capacity(rbd_dev->disk, h.image_size / SECTOR_SIZE); down_write(&rbd_dev->header.snap_rwsem); @@ -1745,6 +1753,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) struct gendisk *disk; struct request_queue *q; int rc; + u64 segment_size; u64 total_size = 0; /* contact OSD, request size info about the object being mapped */ @@ -1780,11 +1789,15 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) if (!q) goto out_disk; + /* We use the default size, but let's be explicit about it. */ + blk_queue_physical_block_size(q, SECTOR_SIZE); + /* set io sizes to object size */ - blk_queue_max_hw_sectors(q, rbd_obj_bytes(&rbd_dev->header) / 512ULL); - blk_queue_max_segment_size(q, rbd_obj_bytes(&rbd_dev->header)); - blk_queue_io_min(q, rbd_obj_bytes(&rbd_dev->header)); - blk_queue_io_opt(q, rbd_obj_bytes(&rbd_dev->header)); + segment_size = rbd_obj_bytes(&rbd_dev->header); + blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE); + blk_queue_max_segment_size(q, segment_size); + blk_queue_io_min(q, segment_size); + blk_queue_io_opt(q, segment_size); blk_queue_merge_bvec(q, rbd_merge_bvec); disk->queue = q; @@ -1795,7 +1808,7 @@ static int rbd_init_disk(struct rbd_device *rbd_dev) rbd_dev->q = q; /* finally, announce the disk to the world */ - set_capacity(disk, total_size / 512ULL); + set_capacity(disk, total_size / SECTOR_SIZE); add_disk(disk); pr_info("%s: added with size 0x%llx\n", @@ -1812,10 +1825,15 @@ out: sysfs */ +static struct rbd_device *dev_to_rbd_dev(struct device *dev) +{ + return container_of(dev, struct rbd_device, dev); +} + static ssize_t rbd_size_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "%llu\n", (unsigned long long)rbd_dev->header.image_size); } @@ -1823,7 +1841,7 @@ static ssize_t rbd_size_show(struct device *dev, static ssize_t rbd_major_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "%d\n", rbd_dev->major); } @@ -1831,7 +1849,7 @@ static ssize_t rbd_major_show(struct device *dev, static ssize_t rbd_client_id_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "client%lld\n", ceph_client_id(rbd_dev->rbd_client->client)); @@ -1840,7 +1858,7 @@ static ssize_t rbd_client_id_show(struct device *dev, static ssize_t rbd_pool_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "%s\n", rbd_dev->pool_name); } @@ -1848,7 +1866,7 @@ static ssize_t rbd_pool_show(struct device *dev, static ssize_t rbd_name_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "%s\n", rbd_dev->obj); } @@ -1857,7 +1875,7 @@ static ssize_t rbd_snap_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); return sprintf(buf, "%s\n", rbd_dev->snap_name); } @@ -1867,7 +1885,7 @@ static ssize_t rbd_image_refresh(struct device *dev, const char *buf, size_t size) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); int rc; int ret = size; @@ -1932,7 +1950,7 @@ static ssize_t rbd_snap_size_show(struct device *dev, { struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); - return sprintf(buf, "%lld\n", (long long)snap->size); + return sprintf(buf, "%zd\n", snap->size); } static ssize_t rbd_snap_id_show(struct device *dev, @@ -1941,7 +1959,7 @@ static ssize_t rbd_snap_id_show(struct device *dev, { struct rbd_snap *snap = container_of(dev, struct rbd_snap, dev); - return sprintf(buf, "%lld\n", (long long)snap->id); + return sprintf(buf, "%llu\n", (unsigned long long) snap->id); } static DEVICE_ATTR(snap_size, S_IRUGO, rbd_snap_size_show, NULL); @@ -2232,7 +2250,8 @@ static void rbd_id_put(struct rbd_device *rbd_dev) /* * Skips over white space at *buf, and updates *buf to point to the * first found non-space character (if any). Returns the length of - * the token (string of non-white space characters) found. + * the token (string of non-white space characters) found. Note + * that *buf must be terminated with '\0'. */ static inline size_t next_token(const char **buf) { @@ -2250,13 +2269,14 @@ static inline size_t next_token(const char **buf) /* * Finds the next token in *buf, and if the provided token buffer is * big enough, copies the found token into it. The result, if - * copied, is guaranteed to be terminated with '\0'. + * copied, is guaranteed to be terminated with '\0'. Note that *buf + * must be terminated with '\0' on entry. * * Returns the length of the token found (not including the '\0'). * Return value will be 0 if no token is found, and it will be >= * token_size if the token would not fit. * - * The *buf pointer will be updated point beyond the end of the + * The *buf pointer will be updated to point beyond the end of the * found token. Note that this occurs even if the token buffer is * too small to hold it. */ @@ -2456,8 +2476,7 @@ static struct rbd_device *__rbd_get_dev(unsigned long id) static void rbd_dev_release(struct device *dev) { - struct rbd_device *rbd_dev = - container_of(dev, struct rbd_device, dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); if (rbd_dev->watch_request) { struct ceph_client *client = rbd_dev->rbd_client->client; @@ -2520,7 +2539,7 @@ static ssize_t rbd_snap_add(struct device *dev, const char *buf, size_t count) { - struct rbd_device *rbd_dev = dev_to_rbd(dev); + struct rbd_device *rbd_dev = dev_to_rbd_dev(dev); int ret; char *name = kmalloc(count + 1, GFP_KERNEL); if (!name) diff --git a/drivers/block/rbd_types.h b/drivers/block/rbd_types.h index fc6c678aa2cb..950708688f17 100644 --- a/drivers/block/rbd_types.h +++ b/drivers/block/rbd_types.h @@ -41,10 +41,6 @@ #define RBD_HEADER_SIGNATURE "RBD" #define RBD_HEADER_VERSION "001.005" -struct rbd_info { - __le64 max_id; -} __attribute__ ((packed)); - struct rbd_image_snap_ondisk { __le64 id; __le64 image_size;