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xen/blkback: Fixed up comments and converted spaces to tabs. 

Suggested-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2011-05-11 15:57:09 -04:00
parent 3d68b39926
commit 01f37f2d53
3 changed files with 103 additions and 79 deletions
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70
drivers/block/xen-blkback/blkback.c
View File

@ -73,13 +73,13 @@ module_param(debug_lvl, int, 0644);
* response queued for it, with the saved 'id' passed back.
*/
struct pending_req {
struct blkif_st *blkif;
u64 id;
int nr_pages;
atomic_t pendcnt;
unsigned short operation;
int status;
struct list_head free_list;
struct blkif_st *blkif;
u64 id;
int nr_pages;
atomic_t pendcnt;
unsigned short operation;
int status;
struct list_head free_list;
};
#define BLKBACK_INVALID_HANDLE (~0)
@ -103,7 +103,8 @@ static struct xen_blkbk *blkbk;
* Little helpful macro to figure out the index and virtual address of the
* pending_pages[..]. For each 'pending_req' we have have up to
* BLKIF_MAX_SEGMENTS_PER_REQUEST (11) pages. The seg would be from 0 through
* 10 and would index in the pending_pages[..]. */
* 10 and would index in the pending_pages[..].
*/
static inline int vaddr_pagenr(struct pending_req *req, int seg)
{
return (req - blkbk->pending_reqs) *
@ -167,8 +168,6 @@ static void free_req(struct pending_req *req)
/*
* Routines for managing virtual block devices (vbds).
*/
static int vbd_translate(struct phys_req *req, struct blkif_st *blkif,
int operation)
{
@ -315,7 +314,7 @@ struct seg_buf {
/*
* Unmap the grant references, and also remove the M2P over-rides
* used in the 'pending_req'.
*/
*/
static void xen_blkbk_unmap(struct pending_req *req)
{
struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
@ -336,27 +335,32 @@ static void xen_blkbk_unmap(struct pending_req *req)
ret = HYPERVISOR_grant_table_op(
GNTTABOP_unmap_grant_ref, unmap, invcount);
BUG_ON(ret);
/* Note, we use invcount, so nr->pages, so we can't index
/*
* Note, we use invcount, so nr->pages, so we can't index
* using vaddr(req, i).
*/
for (i = 0; i < invcount; i++) {
ret = m2p_remove_override(
virt_to_page(unmap[i].host_addr), false);
if (ret) {
printk(KERN_ALERT "Failed to remove M2P override for " \
"%lx\n", (unsigned long)unmap[i].host_addr);
printk(KERN_ALERT "Failed to remove M2P override for %lx\n",
(unsigned long)unmap[i].host_addr);
continue;
}
}
}
static int xen_blkbk_map(struct blkif_request *req, struct pending_req *pending_req,
static int xen_blkbk_map(struct blkif_request *req,
struct pending_req *pending_req,
struct seg_buf seg[])
{
struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST];
int i;
int nseg = req->nr_segments;
int ret = 0;
/* Fill out preq.nr_sects with proper amount of sectors, and setup
/*
* Fill out preq.nr_sects with proper amount of sectors, and setup
* assign map[..] with the PFN of the page in our domain with the
* corresponding grant reference for each page.
*/
@ -367,13 +371,15 @@ static int xen_blkbk_map(struct blkif_request *req, struct pending_req *pending_
if (pending_req->operation != BLKIF_OP_READ)
flags |= GNTMAP_readonly;
gnttab_set_map_op(&map[i], vaddr(pending_req, i), flags,
req->u.rw.seg[i].gref, pending_req->blkif->domid);
req->u.rw.seg[i].gref,
pending_req->blkif->domid);
}
ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map, nseg);
BUG_ON(ret);
/* Now swizzel the MFN in our domain with the MFN from the other domain
/*
* Now swizzle the MFN in our domain with the MFN from the other domain
* so that when we access vaddr(pending_req,i) it has the contents of
* the page from the other domain.
*/
@ -423,7 +429,8 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
pending_req->status = BLKIF_RSP_ERROR;
}
/* If all of the bio's have completed it is time to unmap
/*
* If all of the bio's have completed it is time to unmap
* the grant references associated with 'request' and provide
* the proper response on the ring.
*/
@ -510,8 +517,8 @@ static int do_block_io_op(struct blkif_st *blkif)
}
/*
* Transumation of the 'struct blkif_request' to a proper 'struct bio'
* and call the 'submit_bio' to pass it to the underlaying storage.
* Transmutation of the 'struct blkif_request' to a proper 'struct bio'
* and call the 'submit_bio' to pass it to the underlying storage.
*/
static int dispatch_rw_block_io(struct blkif_st *blkif,
struct blkif_request *req,
@ -538,8 +545,10 @@ static int dispatch_rw_block_io(struct blkif_st *blkif,
case BLKIF_OP_FLUSH_DISKCACHE:
blkif->st_f_req++;
operation = WRITE_FLUSH;
/* The frontend likes to set this to -1, which vbd_translate
* is alergic too. */
/*
* The frontend likes to set this to -1, which vbd_translate
* is alergic too.
*/
req->u.rw.sector_number = 0;
break;
case BLKIF_OP_WRITE_BARRIER:
@ -585,8 +594,11 @@ static int dispatch_rw_block_io(struct blkif_st *blkif,
preq.sector_number + preq.nr_sects, preq.dev);
goto fail_response;
}
/* This check _MUST_ be done after vbd_translate as the preq.bdev
* is set there. */
/*
* This check _MUST_ be done after vbd_translate as the preq.bdev
* is set there.
*/
for (i = 0; i < nseg; i++) {
if (((int)preq.sector_number|(int)seg[i].nsec) &
((bdev_logical_block_size(preq.bdev) >> 9) - 1)) {
@ -595,7 +607,9 @@ static int dispatch_rw_block_io(struct blkif_st *blkif,
goto fail_response;
}
}
/* If we have failed at this point, we need to undo the M2P override,
/*
* If we have failed at this point, we need to undo the M2P override,
* set gnttab_set_unmap_op on all of the grant references and perform
* the hypercall to unmap the grants - that is all done in
* xen_blkbk_unmap.
@ -638,8 +652,8 @@ static int dispatch_rw_block_io(struct blkif_st *blkif,
bio->bi_end_io = end_block_io_op;
}
/* We set it one so that the last submit_bio does not have to call
/*
* We set it one so that the last submit_bio does not have to call
* atomic_inc.
*/
atomic_set(&pending_req->pendcnt, nbio);

73
drivers/block/xen-blkback/common.h
View File

@ -47,53 +47,58 @@
__FILE__ , __LINE__ , ## _a)
struct vbd {
blkif_vdev_t handle; /* what the domain refers to this vbd as */
unsigned char readonly; /* Non-zero -> read-only */
unsigned char type; /* VDISK_xxx */
u32 pdevice; /* phys device that this vbd maps to */
struct block_device *bdev;
sector_t size; /* Cached size parameter */
bool flush_support;
/* What the domain refers to this vbd as. */
blkif_vdev_t handle;
/* Non-zero -> read-only */
unsigned char readonly;
/* VDISK_xxx */
unsigned char type;
/* phys device that this vbd maps to. */
u32 pdevice;
struct block_device *bdev;
/* Cached size parameter. */
sector_t size;
bool flush_support;
};
struct backend_info;
struct blkif_st {
/* Unique identifier for this interface. */
domid_t domid;
unsigned int handle;
domid_t domid;
unsigned int handle;
/* Physical parameters of the comms window. */
unsigned int irq;
unsigned int irq;
/* Comms information. */
enum blkif_protocol blk_protocol;
union blkif_back_rings blk_rings;
struct vm_struct *blk_ring_area;
enum blkif_protocol blk_protocol;
union blkif_back_rings blk_rings;
struct vm_struct *blk_ring_area;
/* The VBD attached to this interface. */
struct vbd vbd;
struct vbd vbd;
/* Back pointer to the backend_info. */
struct backend_info *be;
struct backend_info *be;
/* Private fields. */
spinlock_t blk_ring_lock;
atomic_t refcnt;
spinlock_t blk_ring_lock;
atomic_t refcnt;
wait_queue_head_t wq;
wait_queue_head_t wq;
/* One thread per one blkif. */
struct task_struct *xenblkd;
unsigned int waiting_reqs;
struct task_struct *xenblkd;
unsigned int waiting_reqs;
/* statistics */
unsigned long st_print;
int st_rd_req;
int st_wr_req;
int st_oo_req;
int st_f_req;
int st_rd_sect;
int st_wr_sect;
unsigned long st_print;
int st_rd_req;
int st_wr_req;
int st_oo_req;
int st_f_req;
int st_rd_sect;
int st_wr_sect;
wait_queue_head_t waiting_to_free;
wait_queue_head_t waiting_to_free;
grant_handle_t shmem_handle;
grant_ref_t shmem_ref;
grant_handle_t shmem_handle;
grant_ref_t shmem_ref;
};
@ -109,10 +114,10 @@ struct blkif_st {
} while (0)
struct phys_req {
unsigned short dev;
unsigned short nr_sects;
struct block_device *bdev;
blkif_sector_t sector_number;
unsigned short dev;
unsigned short nr_sects;
struct block_device *bdev;
blkif_sector_t sector_number;
};
int xen_blkif_interface_init(void);

39
drivers/block/xen-blkback/xenbus.c
View File

@ -27,12 +27,12 @@
__func__, __LINE__, ##args)
struct backend_info {
struct xenbus_device *dev;
struct blkif_st *blkif;
struct xenbus_watch backend_watch;
unsigned major;
unsigned minor;
char *mode;
struct xenbus_device *dev;
struct blkif_st *blkif;
struct xenbus_watch backend_watch;
unsigned major;
unsigned minor;
char *mode;
};
static struct kmem_cache *xen_blkif_cachep;
@ -425,7 +425,7 @@ int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
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
* the device's physical major and minor numbers. Switch to InitWait.
@ -473,7 +473,7 @@ fail:
}
/**
/*
* Callback received when the hotplug scripts have placed the physical-device
* node. Read it and the mode node, and create a vbd. If the frontend is
* ready, connect.
@ -495,9 +495,11 @@ static void backend_changed(struct xenbus_watch *watch,
err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x",
&major, &minor);
if (XENBUS_EXIST_ERR(err)) {
/* Since this watch will fire once immediately after it is
registered, we expect this. Ignore it, and wait for the
hotplug scripts. */
/*
* Since this watch will fire once immediately after it is
* registered, we expect this. Ignore it, and wait for the
* hotplug scripts.
*/
return;
}
if (err != 2) {
@ -562,7 +564,7 @@ static void backend_changed(struct xenbus_watch *watch,
}
/**
/*
* Callback received when the frontend's state changes.
*/
static void frontend_changed(struct xenbus_device *dev,
@ -584,13 +586,16 @@ static void frontend_changed(struct xenbus_device *dev,
case XenbusStateInitialised:
case XenbusStateConnected:
/* Ensure we connect even when two watches fire in
close successsion and we miss the intermediate value
of frontend_state. */
/*
* Ensure we connect even when two watches fire in
* close successsion and we miss the intermediate value
* of frontend_state.
*/
if (dev->state == XenbusStateConnected)
break;
/* Enforce precondition before potential leak point.
/*
* Enforce precondition before potential leak point.
* blkif_disconnect() is idempotent.
*/
xen_blkif_disconnect(be->blkif);
@ -627,7 +632,7 @@ static void frontend_changed(struct xenbus_device *dev,
/* ** Connection ** */
/**
/*
* Write the physical details regarding the block device to the store, and
* switch to Connected state.
*/