diff options
| -rw-r--r-- | drivers/block/xen-blkback/blkback.c | 86 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 93 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 58 |
3 files changed, 206 insertions, 31 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 2330a9ad5e95..9713d5a490e4 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -39,6 +39,9 @@ #include <linux/list.h> #include <linux/delay.h> #include <linux/freezer.h> +#include <linux/loop.h> +#include <linux/falloc.h> +#include <linux/fs.h> #include <xen/events.h> #include <xen/page.h> @@ -258,13 +261,16 @@ irqreturn_t xen_blkif_be_int(int irq, void *dev_id) static void print_stats(struct xen_blkif *blkif) { - pr_info("xen-blkback (%s): oo %3d | rd %4d | wr %4d | f %4d\n", + pr_info("xen-blkback (%s): oo %3d | rd %4d | wr %4d | f %4d" + " | ds %4d\n", current->comm, blkif->st_oo_req, - blkif->st_rd_req, blkif->st_wr_req, blkif->st_f_req); + blkif->st_rd_req, blkif->st_wr_req, + blkif->st_f_req, blkif->st_ds_req); blkif->st_print = jiffies + msecs_to_jiffies(10 * 1000); blkif->st_rd_req = 0; blkif->st_wr_req = 0; blkif->st_oo_req = 0; + blkif->st_ds_req = 0; } int xen_blkif_schedule(void *arg) @@ -410,6 +416,42 @@ static int xen_blkbk_map(struct blkif_request *req, return ret; } +static void xen_blk_discard(struct xen_blkif *blkif, struct blkif_request *req) +{ + int err = 0; + int status = BLKIF_RSP_OKAY; + struct block_device *bdev = blkif->vbd.bdev; + + if (blkif->blk_backend_type == BLKIF_BACKEND_PHY) + /* just forward the discard request */ + err = blkdev_issue_discard(bdev, + req->u.discard.sector_number, + req->u.discard.nr_sectors, + GFP_KERNEL, 0); + else if (blkif->blk_backend_type == BLKIF_BACKEND_FILE) { + /* punch a hole in the backing file */ + struct loop_device *lo = bdev->bd_disk->private_data; + struct file *file = lo->lo_backing_file; + + if (file->f_op->fallocate) + err = file->f_op->fallocate(file, + FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, + req->u.discard.sector_number << 9, + req->u.discard.nr_sectors << 9); + else + err = -EOPNOTSUPP; + } else + err = -EOPNOTSUPP; + + if (err == -EOPNOTSUPP) { + pr_debug(DRV_PFX "discard op failed, not supported\n"); + status = BLKIF_RSP_EOPNOTSUPP; + } else if (err) + status = BLKIF_RSP_ERROR; + + make_response(blkif, req->id, req->operation, status); +} + /* * Completion callback on the bio's. Called as bh->b_end_io() */ @@ -563,6 +605,10 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, blkif->st_f_req++; operation = WRITE_FLUSH; break; + case BLKIF_OP_DISCARD: + blkif->st_ds_req++; + operation = REQ_DISCARD; + break; case BLKIF_OP_WRITE_BARRIER: default: operation = 0; /* make gcc happy */ @@ -572,7 +618,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, /* Check that the number of segments is sane. */ nseg = req->nr_segments; - if (unlikely(nseg == 0 && operation != WRITE_FLUSH) || + if (unlikely(nseg == 0 && operation != WRITE_FLUSH && + operation != REQ_DISCARD) || unlikely(nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) { pr_debug(DRV_PFX "Bad number of segments in request (%d)\n", nseg); @@ -627,10 +674,14 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, * the hypercall to unmap the grants - that is all done in * xen_blkbk_unmap. */ - if (xen_blkbk_map(req, pending_req, seg)) + if (operation != BLKIF_OP_DISCARD && + xen_blkbk_map(req, pending_req, seg)) goto fail_flush; - /* This corresponding xen_blkif_put is done in __end_block_io_op */ + /* + * This corresponding xen_blkif_put is done in __end_block_io_op, or + * below (in "!bio") if we are handling a BLKIF_OP_DISCARD. + */ xen_blkif_get(blkif); for (i = 0; i < nseg; i++) { @@ -654,18 +705,25 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, preq.sector_number += seg[i].nsec; } - /* This will be hit if the operation was a flush. */ + /* This will be hit if the operation was a flush or discard. */ if (!bio) { - BUG_ON(operation != WRITE_FLUSH); + BUG_ON(operation != WRITE_FLUSH && operation != REQ_DISCARD); - bio = bio_alloc(GFP_KERNEL, 0); - if (unlikely(bio == NULL)) - goto fail_put_bio; + if (operation == WRITE_FLUSH) { + bio = bio_alloc(GFP_KERNEL, 0); + if (unlikely(bio == NULL)) + goto fail_put_bio; - biolist[nbio++] = bio; - bio->bi_bdev = preq.bdev; - bio->bi_private = pending_req; - bio->bi_end_io = end_block_io_op; + biolist[nbio++] = bio; + bio->bi_bdev = preq.bdev; + bio->bi_private = pending_req; + bio->bi_end_io = end_block_io_op; + } else if (operation == REQ_DISCARD) { + xen_blk_discard(blkif, req); + xen_blkif_put(blkif); + free_req(pending_req); + return 0; + } } /* diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 9e40b283a468..bfb532ea5b1b 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -63,13 +63,26 @@ struct blkif_common_response { /* i386 protocol version */ #pragma pack(push, 4) + +struct blkif_x86_32_request_rw { + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; +}; + +struct blkif_x86_32_request_discard { + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + uint64_t nr_sectors; +}; + struct blkif_x86_32_request { uint8_t operation; /* BLKIF_OP_??? */ uint8_t nr_segments; /* number of segments */ blkif_vdev_t handle; /* only for read/write requests */ uint64_t id; /* private guest value, echoed in resp */ - blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ - struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + union { + struct blkif_x86_32_request_rw rw; + struct blkif_x86_32_request_discard discard; + } u; }; struct blkif_x86_32_response { uint64_t id; /* copied from request */ @@ -79,13 +92,26 @@ struct blkif_x86_32_response { #pragma pack(pop) /* x86_64 protocol version */ + +struct blkif_x86_64_request_rw { + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; +}; + +struct blkif_x86_64_request_discard { + blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ + uint64_t nr_sectors; +}; + struct blkif_x86_64_request { uint8_t operation; /* BLKIF_OP_??? */ uint8_t nr_segments; /* number of segments */ blkif_vdev_t handle; /* only for read/write requests */ uint64_t __attribute__((__aligned__(8))) id; - blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ - struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + union { + struct blkif_x86_64_request_rw rw; + struct blkif_x86_64_request_discard discard; + } u; }; struct blkif_x86_64_response { uint64_t __attribute__((__aligned__(8))) id; @@ -113,6 +139,11 @@ enum blkif_protocol { BLKIF_PROTOCOL_X86_64 = 3, }; +enum blkif_backend_type { + BLKIF_BACKEND_PHY = 1, + BLKIF_BACKEND_FILE = 2, +}; + struct xen_vbd { /* What the domain refers to this vbd as. */ blkif_vdev_t handle; @@ -138,6 +169,7 @@ struct xen_blkif { unsigned int irq; /* Comms information. */ enum blkif_protocol blk_protocol; + enum blkif_backend_type blk_backend_type; union blkif_back_rings blk_rings; struct vm_struct *blk_ring_area; /* The VBD attached to this interface. */ @@ -159,6 +191,7 @@ struct xen_blkif { int st_wr_req; int st_oo_req; int st_f_req; + int st_ds_req; int st_rd_sect; int st_wr_sect; @@ -182,7 +215,7 @@ struct xen_blkif { struct phys_req { unsigned short dev; - unsigned short nr_sects; + blkif_sector_t nr_sects; struct block_device *bdev; blkif_sector_t sector_number; }; @@ -206,12 +239,25 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst, dst->nr_segments = src->nr_segments; dst->handle = src->handle; dst->id = src->id; - dst->u.rw.sector_number = src->sector_number; - barrier(); - if (n > dst->nr_segments) - n = dst->nr_segments; - for (i = 0; i < n; i++) - dst->u.rw.seg[i] = src->seg[i]; + switch (src->operation) { + case BLKIF_OP_READ: + case BLKIF_OP_WRITE: + case BLKIF_OP_WRITE_BARRIER: + case BLKIF_OP_FLUSH_DISKCACHE: + dst->u.rw.sector_number = src->u.rw.sector_number; + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; + for (i = 0; i < n; i++) + dst->u.rw.seg[i] = src->u.rw.seg[i]; + break; + case BLKIF_OP_DISCARD: + dst->u.discard.sector_number = src->u.discard.sector_number; + dst->u.discard.nr_sectors = src->u.discard.nr_sectors; + break; + default: + break; + } } static inline void blkif_get_x86_64_req(struct blkif_request *dst, @@ -222,12 +268,25 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst, dst->nr_segments = src->nr_segments; dst->handle = src->handle; dst->id = src->id; - dst->u.rw.sector_number = src->sector_number; - barrier(); - if (n > dst->nr_segments) - n = dst->nr_segments; - for (i = 0; i < n; i++) - dst->u.rw.seg[i] = src->seg[i]; + switch (src->operation) { + case BLKIF_OP_READ: + case BLKIF_OP_WRITE: + case BLKIF_OP_WRITE_BARRIER: + case BLKIF_OP_FLUSH_DISKCACHE: + dst->u.rw.sector_number = src->u.rw.sector_number; + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; + for (i = 0; i < n; i++) + dst->u.rw.seg[i] = src->u.rw.seg[i]; + break; + case BLKIF_OP_DISCARD: + dst->u.discard.sector_number = src->u.discard.sector_number; + dst->u.discard.nr_sectors = src->u.discard.nr_sectors; + break; + default: + break; + } } #endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */ diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 3f129b45451a..2b3aef0332f3 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -272,6 +272,7 @@ VBD_SHOW(oo_req, "%d\n", be->blkif->st_oo_req); VBD_SHOW(rd_req, "%d\n", be->blkif->st_rd_req); VBD_SHOW(wr_req, "%d\n", be->blkif->st_wr_req); VBD_SHOW(f_req, "%d\n", be->blkif->st_f_req); +VBD_SHOW(ds_req, "%d\n", be->blkif->st_ds_req); VBD_SHOW(rd_sect, "%d\n", be->blkif->st_rd_sect); VBD_SHOW(wr_sect, "%d\n", be->blkif->st_wr_sect); @@ -280,6 +281,7 @@ static struct attribute *xen_vbdstat_attrs[] = { &dev_attr_rd_req.attr, &dev_attr_wr_req.attr, &dev_attr_f_req.attr, + &dev_attr_ds_req.attr, &dev_attr_rd_sect.attr, &dev_attr_wr_sect.attr, NULL @@ -419,6 +421,60 @@ int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, return err; } +int xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) +{ + struct xenbus_device *dev = be->dev; + struct xen_blkif *blkif = be->blkif; + char *type; + int err; + int state = 0; + + type = xenbus_read(XBT_NIL, dev->nodename, "type", NULL); + if (!IS_ERR(type)) { + if (strncmp(type, "file", 4) == 0) { + state = 1; + blkif->blk_backend_type = BLKIF_BACKEND_FILE; + } + if (strncmp(type, "phy", 3) == 0) { + struct block_device *bdev = be->blkif->vbd.bdev; + struct request_queue *q = bdev_get_queue(bdev); + if (blk_queue_discard(q)) { + err = xenbus_printf(xbt, dev->nodename, + "discard-granularity", "%u", + q->limits.discard_granularity); + if (err) { + xenbus_dev_fatal(dev, err, + "writing discard-granularity"); + goto kfree; + } + err = xenbus_printf(xbt, dev->nodename, + "discard-alignment", "%u", + q->limits.discard_alignment); + if (err) { + xenbus_dev_fatal(dev, err, + "writing discard-alignment"); + goto kfree; + } + state = 1; + blkif->blk_backend_type = BLKIF_BACKEND_PHY; + } + } + } else { + err = PTR_ERR(type); + xenbus_dev_fatal(dev, err, "reading type"); + goto out; + } + + err = xenbus_printf(xbt, dev->nodename, "feature-discard", + "%d", state); + if (err) + xenbus_dev_fatal(dev, err, "writing feature-discard"); +kfree: + kfree(type); +out: + return err; +} + /* * Entry point to this code when a new device is created. Allocate the basic * structures, and watch the store waiting for the hotplug scripts to tell us @@ -650,6 +706,8 @@ again: if (err) goto abort; + err = xen_blkbk_discard(xbt, be); + err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", (unsigned long long)vbd_sz(&be->blkif->vbd)); if (err) { |