[Devel] [PATCH rh7 1/4] ploop: introduce pbd
Dmitry Monakhov
dmonakhov at openvz.org
Sat Apr 30 10:01:33 PDT 2016
Maxim Patlasov <mpatlasov at virtuozzo.com> writes:
> The patch introduce push_backup descriptor ("pbd") and a few simple
> functions to create and release it.
>
> Userspace can govern it by new ioctls: PLOOP_IOC_PUSH_BACKUP_INIT and
> PLOOP_IOC_PUSH_BACKUP_STOP.
Acked-by: Dmitry Monakhov <dmonakhov at openvz.org>
>
> Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
> ---
> drivers/block/ploop/Makefile | 2
> drivers/block/ploop/dev.c | 89 ++++++++++++
> drivers/block/ploop/push_backup.c | 271 +++++++++++++++++++++++++++++++++++++
> drivers/block/ploop/push_backup.h | 8 +
> include/linux/ploop/ploop.h | 3
> include/linux/ploop/ploop_if.h | 19 +++
> 6 files changed, 391 insertions(+), 1 deletion(-)
> create mode 100644 drivers/block/ploop/push_backup.c
> create mode 100644 drivers/block/ploop/push_backup.h
>
> diff --git a/drivers/block/ploop/Makefile b/drivers/block/ploop/Makefile
> index e36a027..0fecf16 100644
> --- a/drivers/block/ploop/Makefile
> +++ b/drivers/block/ploop/Makefile
> @@ -5,7 +5,7 @@ CFLAGS_io_direct.o = -I$(src)
> CFLAGS_ploop_events.o = -I$(src)
>
> obj-$(CONFIG_BLK_DEV_PLOOP) += ploop.o
> -ploop-objs := dev.o map.o io.o sysfs.o tracker.o freeblks.o ploop_events.o discard.o
> +ploop-objs := dev.o map.o io.o sysfs.o tracker.o freeblks.o ploop_events.o discard.o push_backup.o
>
> obj-$(CONFIG_BLK_DEV_PLOOP) += pfmt_ploop1.o
> pfmt_ploop1-objs := fmt_ploop1.o
> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
> index 1da073c..23da9f5 100644
> --- a/drivers/block/ploop/dev.c
> +++ b/drivers/block/ploop/dev.c
> @@ -19,6 +19,7 @@
> #include "ploop_events.h"
> #include "freeblks.h"
> #include "discard.h"
> +#include "push_backup.h"
>
> /* Structures and terms:
> *
> @@ -3766,6 +3767,9 @@ static int ploop_stop(struct ploop_device * plo, struct block_device *bdev)
> return -EBUSY;
> }
>
> + clear_bit(PLOOP_S_PUSH_BACKUP, &plo->state);
> + ploop_pb_stop(plo->pbd);
> +
> for (p = plo->disk->minors - 1; p > 0; p--)
> invalidate_partition(plo->disk, p);
> invalidate_partition(plo->disk, 0);
> @@ -3892,6 +3896,7 @@ static int ploop_clear(struct ploop_device * plo, struct block_device * bdev)
> }
>
> ploop_fb_fini(plo->fbd, 0);
> + ploop_pb_fini(plo->pbd);
>
> plo->maintenance_type = PLOOP_MNTN_OFF;
> plo->bd_size = 0;
> @@ -4477,6 +4482,84 @@ static int ploop_getdevice_ioc(unsigned long arg)
> return err;
> }
>
> +static int ploop_push_backup_init(struct ploop_device *plo, unsigned long arg)
> +{
> + struct ploop_push_backup_init_ctl ctl;
> + struct ploop_pushbackup_desc *pbd = NULL;
> + int rc = 0;
> +
> + if (list_empty(&plo->map.delta_list))
> + return -ENOENT;
> +
> + if (plo->maintenance_type != PLOOP_MNTN_OFF)
> + return -EINVAL;
> +
> + BUG_ON(plo->pbd);
> +
> + if (copy_from_user(&ctl, (void*)arg, sizeof(ctl)))
> + return -EFAULT;
> +
> + pbd = ploop_pb_alloc(plo);
> + if (!pbd) {
> + rc = -ENOMEM;
> + goto pb_init_done;
> + }
> +
> + ploop_quiesce(plo);
> +
> + rc = ploop_pb_init(pbd, ctl.cbt_uuid, !ctl.cbt_mask_addr);
> + if (rc) {
> + ploop_relax(plo);
> + goto pb_init_done;
> + }
> +
> + plo->pbd = pbd;
> +
> + atomic_set(&plo->maintenance_cnt, 0);
> + plo->maintenance_type = PLOOP_MNTN_PUSH_BACKUP;
> + set_bit(PLOOP_S_PUSH_BACKUP, &plo->state);
> +
> + ploop_relax(plo);
> +
> + if (ctl.cbt_mask_addr)
> + rc = ploop_pb_copy_cbt_to_user(pbd, (char *)ctl.cbt_mask_addr);
> +pb_init_done:
> + if (rc)
> + ploop_pb_fini(pbd);
> + return rc;
> +}
> +
> +static int ploop_push_backup_stop(struct ploop_device *plo, unsigned long arg)
> +{
> + struct ploop_pushbackup_desc *pbd = plo->pbd;
> + struct ploop_push_backup_stop_ctl ctl;
> +
> + if (plo->maintenance_type != PLOOP_MNTN_PUSH_BACKUP)
> + return -EINVAL;
> +
> + if (copy_from_user(&ctl, (void*)arg, sizeof(ctl)))
> + return -EFAULT;
> +
> + if (pbd && ploop_pb_check_uuid(pbd, ctl.cbt_uuid)) {
> + printk("ploop(%d): PUSH_BACKUP_STOP uuid mismatch\n",
> + plo->index);
> + return -EINVAL;
> + }
> +
> + if (!test_and_clear_bit(PLOOP_S_PUSH_BACKUP, &plo->state))
> + return -EINVAL;
> +
> + BUG_ON (!pbd);
> + ctl.status = ploop_pb_stop(pbd);
> +
> + ploop_quiesce(plo);
> + ploop_pb_fini(plo->pbd);
> + plo->maintenance_type = PLOOP_MNTN_OFF;
> + ploop_relax(plo);
> +
> + return 0;
> +}
> +
> static int ploop_ioctl(struct block_device *bdev, fmode_t fmode, unsigned int cmd,
> unsigned long arg)
> {
> @@ -4581,6 +4664,12 @@ static int ploop_ioctl(struct block_device *bdev, fmode_t fmode, unsigned int cm
> case PLOOP_IOC_MAX_DELTA_SIZE:
> err = ploop_set_max_delta_size(plo, arg);
> break;
> + case PLOOP_IOC_PUSH_BACKUP_INIT:
> + err = ploop_push_backup_init(plo, arg);
> + break;
> + case PLOOP_IOC_PUSH_BACKUP_STOP:
> + err = ploop_push_backup_stop(plo, arg);
> + break;
> default:
> err = -EINVAL;
> }
> diff --git a/drivers/block/ploop/push_backup.c b/drivers/block/ploop/push_backup.c
> new file mode 100644
> index 0000000..ecc9862
> --- /dev/null
> +++ b/drivers/block/ploop/push_backup.c
> @@ -0,0 +1,271 @@
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/sched.h>
> +#include <linux/fs.h>
> +#include <linux/file.h>
> +#include <linux/bio.h>
> +#include <linux/interrupt.h>
> +#include <linux/buffer_head.h>
> +#include <linux/kthread.h>
> +
> +#include <trace/events/block.h>
> +
> +#include <linux/ploop/ploop.h>
> +#include "push_backup.h"
> +
> +#define NR_PAGES(bits) (((bits) + PAGE_SIZE*8 - 1) / (PAGE_SIZE*8))
> +#define BITS_PER_PAGE (1UL << (PAGE_SHIFT + 3))
> +
> +struct ploop_pushbackup_desc {
> + struct ploop_device *plo;
> + struct page **cbt_map; /* a 'snapshot' copy of CBT mask */
> + blkcnt_t cbt_block_max;
> + blkcnt_t cbt_block_bits;
> + __u8 cbt_uuid[16];
> +
> + struct page **ppb_map; /* Ploop Push Backup mask */
> + cluster_t ppb_block_max; /* first invalid index in ppb_map */
> + cluster_t ppb_offset; /* [0, ppb_offset) is ACKed by userspace */
> +
> + spinlock_t ppb_lock;
> + struct completion ppb_comp;
> + bool ppb_waiting;
> +
> +
> + struct rb_root pending_tree;
> + struct rb_root reported_tree;
> +};
> +
> +int ploop_pb_check_uuid(struct ploop_pushbackup_desc *pbd, __u8 *uuid)
> +{
> + if (memcmp(pbd->cbt_uuid, uuid, sizeof(pbd->cbt_uuid)))
> + return -1;
> + return 0;
> +}
> +
> +struct ploop_pushbackup_desc *ploop_pb_alloc(struct ploop_device *plo)
> +{
> + struct ploop_pushbackup_desc *pbd;
> + int i, npages;
> +
> + pbd = kmalloc(sizeof(struct ploop_pushbackup_desc), GFP_KERNEL|__GFP_ZERO);
> + if (pbd == NULL)
> + return NULL;
> +
> + pbd->ppb_block_max = (plo->bd_size + (1 << plo->cluster_log) - 1)
> + >> plo->cluster_log;
> + npages = NR_PAGES(pbd->ppb_block_max);
> +
> + pbd->ppb_map = vmalloc(npages * sizeof(void *));
> + if (!pbd->ppb_map) {
> + kfree(pbd);
> + return NULL;
> + }
> +
> + memset(pbd->ppb_map, 0, npages * sizeof(void *));
> +
> + for (i = 0; i < npages; i++) {
> + pbd->ppb_map[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
> + if (!pbd->ppb_map[i]) {
> + while (--i >= 0)
> + __free_page(pbd->ppb_map[i]);
> + vfree(pbd->ppb_map);
> + kfree(pbd);
> + return NULL;
> + }
> + }
> +
> + spin_lock_init(&pbd->ppb_lock);
> + init_completion(&pbd->ppb_comp);
> + pbd->pending_tree = RB_ROOT;
> + pbd->reported_tree = RB_ROOT;
> + pbd->plo = plo;
> +
> + return pbd;
> +}
> +
> +static int find_first_blk_in_map(struct page **map, u64 map_max, u64 *blk_p)
> +{
> + u64 blk = *blk_p;
> + unsigned long idx = blk >> (PAGE_SHIFT + 3);
> +
> + while (blk < map_max) {
> + unsigned long off = blk & (BITS_PER_PAGE -1);
> + unsigned long next_bit;
> + struct page *page = map[idx];
> +
> + if (!page)
> + goto next;
> +
> + next_bit = find_next_bit(page_address(page), BITS_PER_PAGE, off);
> + if (next_bit != BITS_PER_PAGE) {
> + *blk_p = ((u64)idx << (PAGE_SHIFT + 3)) + next_bit;
> + return 0;
> + }
> +
> + next:
> + idx++;
> + blk = (u64)idx << (PAGE_SHIFT + 3);
> + }
> +
> + return -1;
> +}
> +
> +enum {
> + SET_BIT,
> + CLEAR_BIT,
> + CHECK_BIT,
> +};
> +
> +static bool do_bit_in_map(struct page **map, u64 map_max, u64 blk, int action)
> +{
> + unsigned long idx = blk >> (PAGE_SHIFT + 3);
> + unsigned long off = blk & (BITS_PER_PAGE -1);
> + struct page *page = map[idx];
> +
> + BUG_ON(blk >= map_max);
> +
> + switch (action) {
> + case SET_BIT:
> + __set_bit(off, page_address(page));
> + break;
> + case CLEAR_BIT:
> + __clear_bit(off, page_address(page));
> + break;
> + case CHECK_BIT:
> + return test_bit(off, page_address(page));
> + default:
> + BUG();
> + }
> +
> + return false;
> +}
> +
> +static void set_bit_in_map(struct page **map, u64 map_max, u64 blk)
> +{
> + do_bit_in_map(map, map_max, blk, SET_BIT);
> +}
> +
> +static int convert_map_to_map(struct ploop_pushbackup_desc *pbd)
> +{
> + struct page **from_map = pbd->cbt_map;
> + blkcnt_t from_max = pbd->cbt_block_max - 1;
> + blkcnt_t from_bits = pbd->cbt_block_bits;
> +
> + struct page **to_map = pbd->ppb_map;
> + cluster_t to_max = pbd->ppb_block_max;
> + int to_bits = pbd->plo->cluster_log + 9;
> +
> + u64 from_blk, to_blk;
> +
> + if ((u64)from_max << from_bits != (u64)to_max << to_bits) {
> + printk("mismatch in map convert: %lu %lu ---> %u %d\n",
> + from_max, from_bits, to_max, to_bits);
> + return -EINVAL;
> + }
> +
> + for (from_blk = 0; from_blk < from_max;
> + from_blk = (++to_blk << to_bits) >> from_bits) {
> +
> + if (find_first_blk_in_map(from_map, from_max, &from_blk))
> + break;
> +
> + to_blk = (from_blk << from_bits) >> to_bits;
> + set_bit_in_map(to_map, to_max, to_blk);
> + }
> +
> + return 0;
> +
> +}
> +
> +int ploop_pb_init(struct ploop_pushbackup_desc *pbd, __u8 *uuid, bool full)
> +{
> + int rc;
> +
> + memcpy(pbd->cbt_uuid, uuid, sizeof(pbd->cbt_uuid));
> +
> + if (full) {
> + int i;
> + for (i = 0; i < NR_PAGES(pbd->ppb_block_max); i++)
> + memset(page_address(pbd->ppb_map[i]), 0xff, PAGE_SIZE);
> + return 0;
> + }
> +
> + rc = blk_cbt_map_copy_once(pbd->plo->queue,
> + uuid,
> + &pbd->cbt_map,
> + &pbd->cbt_block_max,
> + &pbd->cbt_block_bits);
> + if (rc)
> + return rc;
> +
> + return convert_map_to_map(pbd);
> +}
> +
> +static void ploop_pb_free_cbt_map(struct ploop_pushbackup_desc *pbd)
> +{
> + if (pbd->cbt_map) {
> + unsigned long i;
> + for (i = 0; i < NR_PAGES(pbd->cbt_block_max); i++)
> + if (pbd->cbt_map[i])
> + __free_page(pbd->cbt_map[i]);
> +
> + vfree(pbd->cbt_map);
> + pbd->cbt_map = NULL;
> + }
> +}
> +
> +void ploop_pb_fini(struct ploop_pushbackup_desc *pbd)
> +{
> + int i;
> +
> + if (pbd == NULL)
> + return;
> +
> + if (!RB_EMPTY_ROOT(&pbd->pending_tree))
> + printk("ploop_pb_fini: pending_tree is not empty!\n");
> + if (!RB_EMPTY_ROOT(&pbd->reported_tree))
> + printk("ploop_pb_fini: reported_tree is not empty!\n");
> +
> + if (pbd->plo)
> + pbd->plo->pbd = NULL;
> +
> + ploop_pb_free_cbt_map(pbd);
> +
> + for (i = 0; i < NR_PAGES(pbd->ppb_block_max); i++)
> + __free_page(pbd->ppb_map[i]);
> +
> + vfree(pbd->ppb_map);
> + kfree(pbd);
> +}
> +
> +int ploop_pb_copy_cbt_to_user(struct ploop_pushbackup_desc *pbd, char *user_addr)
> +{
> + unsigned long i;
> +
> + for (i = 0; i < NR_PAGES(pbd->cbt_block_max); i++) {
> + struct page *page = pbd->cbt_map[i] ? : ZERO_PAGE(0);
> +
> + if (copy_to_user(user_addr, page_address(page), PAGE_SIZE))
> + return -EFAULT;
> +
> + user_addr += PAGE_SIZE;
> + }
> +
> + ploop_pb_free_cbt_map(pbd);
> + return 0;
> +}
> +
> +unsigned long ploop_pb_stop(struct ploop_pushbackup_desc *pbd)
> +{
> + if (pbd == NULL)
> + return 0;
> +
> + spin_lock(&pbd->ppb_lock);
> +
> + if (pbd->ppb_waiting)
> + complete(&pbd->ppb_comp);
> + spin_unlock(&pbd->ppb_lock);
> +
> + return 0;
> +}
> diff --git a/drivers/block/ploop/push_backup.h b/drivers/block/ploop/push_backup.h
> new file mode 100644
> index 0000000..40d23f5
> --- /dev/null
> +++ b/drivers/block/ploop/push_backup.h
> @@ -0,0 +1,8 @@
> +struct ploop_pushbackup_desc;
> +
> +struct ploop_pushbackup_desc *ploop_pb_alloc(struct ploop_device *plo);
> +int ploop_pb_init(struct ploop_pushbackup_desc *pbd, __u8 *uuid, bool full);
> +void ploop_pb_fini(struct ploop_pushbackup_desc *pbd);
> +int ploop_pb_copy_cbt_to_user(struct ploop_pushbackup_desc *pbd, char *user_addr);
> +unsigned long ploop_pb_stop(struct ploop_pushbackup_desc *pbd);
> +int ploop_pb_check_uuid(struct ploop_pushbackup_desc *pbd, __u8 *uuid);
> diff --git a/include/linux/ploop/ploop.h b/include/linux/ploop/ploop.h
> index c9fb1b0..09f419d3 100644
> --- a/include/linux/ploop/ploop.h
> +++ b/include/linux/ploop/ploop.h
> @@ -53,6 +53,7 @@ enum {
> PLOOP_S_LOCKED, /* ploop is locked by userspace
> (for minor mgmt only) */
> PLOOP_S_ONCE, /* An event (e.g. printk once) happened */
> + PLOOP_S_PUSH_BACKUP, /* Push_backup is in progress */
> };
>
> struct ploop_snapdata
> @@ -337,6 +338,7 @@ struct ploop_stats
> };
>
> struct ploop_freeblks_desc;
> +struct ploop_pushbackup_desc;
>
> struct ploop_device
> {
> @@ -438,6 +440,7 @@ struct ploop_device
> char cookie[PLOOP_COOKIE_SIZE];
>
> struct ploop_freeblks_desc *fbd;
> + struct ploop_pushbackup_desc *pbd;
>
> unsigned long locking_state; /* plo locked by userspace */
> };
> diff --git a/include/linux/ploop/ploop_if.h b/include/linux/ploop/ploop_if.h
> index aacddb3..83a68e5 100644
> --- a/include/linux/ploop/ploop_if.h
> +++ b/include/linux/ploop/ploop_if.h
> @@ -186,6 +186,18 @@ struct ploop_getdevice_ctl
> __u32 __mbz1;
> } __attribute__ ((aligned (8)));
>
> +struct ploop_push_backup_init_ctl
> +{
> + __u8 cbt_uuid[16];
> + __u64 cbt_mask_addr; /* page-aligned space for CBT mask */
> +} __attribute__ ((aligned (8)));
> +
> +struct ploop_push_backup_stop_ctl
> +{
> + __u8 cbt_uuid[16];
> + __u32 status; /* for sanity: non-zero if pending or active queue is not empty */
> +} __attribute__ ((aligned (8)));
> +
> /* maintenance types */
> enum {
> PLOOP_MNTN_OFF = 0, /* no maintenance is in progress */
> @@ -202,6 +214,7 @@ enum {
> PLOOP_MNTN_MERGE, /* merge is in progress */
> PLOOP_MNTN_GROW, /* grow is in progress */
> PLOOP_MNTN_RELOC, /* relocation is in progress */
> + PLOOP_MNTN_PUSH_BACKUP, /* push backup is in progress */
> };
>
> /*
> @@ -302,6 +315,12 @@ struct ploop_track_extent
> /* Set maximum size for the top delta . */
> #define PLOOP_IOC_MAX_DELTA_SIZE _IOW(PLOOPCTLTYPE, 28, __u64)
>
> +/* Start push backup */
> +#define PLOOP_IOC_PUSH_BACKUP_INIT _IOR(PLOOPCTLTYPE, 29, struct ploop_push_backup_init_ctl)
> +
> +/* Stop push backup */
> +#define PLOOP_IOC_PUSH_BACKUP_STOP _IOR(PLOOPCTLTYPE, 31, struct ploop_push_backup_stop_ctl)
> +
> /* Events exposed via /sys/block/ploopN/pstate/event */
> #define PLOOP_EVENT_ABORTED 1
> #define PLOOP_EVENT_STOPPED 2
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