| Message ID | 20170924070247.25560-8-damien.lemoal@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> +static inline unsigned long *sd_zbc_alloc_zone_bitmap(struct scsi_disk *sdkp) > +{ > + struct request_queue *q = sdkp->disk->queue; > + > + return kzalloc_node(BITS_TO_LONGS(sdkp->nr_zones) > + * sizeof(unsigned long), > + GFP_KERNEL, q->node); This really screams for kcalloc_node and friends that I think Johannes volunteered to add. > + * sd_zbc_setup_seq_zones - Initialize the disk request queue zone type bitmap. > + * @sdkp: The disk of the bitmap > + * > + * Allocate a zone bitmap and initialize it by identifying sequential zones. > + */ > +static int sd_zbc_setup_seq_zones(struct scsi_disk *sdkp) > +{ > + struct request_queue *q = sdkp->disk->queue; > + unsigned long *seq_zones; > + sector_t block = 0; > + unsigned char *buf; > + unsigned char *rec; > + unsigned int buf_len; > + unsigned int list_length; > + unsigned int n = 0; > + u8 type, cond; > + int ret = -ENOMEM; > + > + kfree(q->seq_zones); > + q->seq_zones = NULL; We also free the previous version, which isn't documented above. Which in general begs the question: What scheme protects access to q->seq_zones? And the previous patch should probably grow a comment to document that q->seq_zones is entirely managed by the driver. > + /* > + * Parse reported zone descriptors to find sequiential zones. > + * Since read-only and offline zones cannot be written, do not > + * mark them as sequential in the bitmap. > + */ > + list_length = get_unaligned_be32(&buf[0]) + 64; > + rec = buf + 64; > + buf_len = min(list_length, SD_ZBC_BUF_SIZE); > + while (rec < buf + buf_len) { > + type = rec[0] & 0x0f; > + cond = (rec[1] >> 4) & 0xf; > + if (type != ZBC_ZONE_TYPE_CONV && > + cond != ZBC_ZONE_COND_READONLY && > + cond != ZBC_ZONE_COND_OFFLINE) > + set_bit(n, seq_zones); > + block = get_unaligned_be64(&rec[8]) + > + get_unaligned_be64(&rec[16]); > + rec += 64; > + n++; > + } Split this out into a helper?
On 9/24/17 17:07, Christoph Hellwig wrote: >> +static inline unsigned long *sd_zbc_alloc_zone_bitmap(struct scsi_disk *sdkp) >> +{ >> + struct request_queue *q = sdkp->disk->queue; >> + >> + return kzalloc_node(BITS_TO_LONGS(sdkp->nr_zones) >> + * sizeof(unsigned long), >> + GFP_KERNEL, q->node); > > This really screams for kcalloc_node and friends that I think Johannes > volunteered to add. OK. Should I wait for Johannes patches ? That can be easily changed later though. >> + * sd_zbc_setup_seq_zones - Initialize the disk request queue zone type bitmap. >> + * @sdkp: The disk of the bitmap >> + * >> + * Allocate a zone bitmap and initialize it by identifying sequential zones. >> + */ >> +static int sd_zbc_setup_seq_zones(struct scsi_disk *sdkp) >> +{ >> + struct request_queue *q = sdkp->disk->queue; >> + unsigned long *seq_zones; >> + sector_t block = 0; >> + unsigned char *buf; >> + unsigned char *rec; >> + unsigned int buf_len; >> + unsigned int list_length; >> + unsigned int n = 0; >> + u8 type, cond; >> + int ret = -ENOMEM; >> + >> + kfree(q->seq_zones); >> + q->seq_zones = NULL; > > We also free the previous version, which isn't documented above. > Which in general begs the question: What scheme protects access > to q->seq_zones? Yes, indeed, the comments do not mention that. I will add that. As for the protection, there is none necessary I think. The reason is that the previous version free+alloc can only happen if sd_revalidate is called, at which point there are no write commands on-going, so no references to seq_zones. Is this correct/not correct ? I am not even sure if the reallocation/reinit is even necessary though. Since sd_revalidate() will at worst result in the disk capacity going to 0 (if the disk is non responsive for instance), accesses beyond seq_zones size will never happen. And the zone types never change, so it may be better to drop this reallocation+reinit. Same for the zones_wlock bitmap. What do you hink ? > And the previous patch should probably grow a comment to document > that q->seq_zones is entirely managed by the driver. Will do. >> + /* >> + * Parse reported zone descriptors to find sequiential zones. >> + * Since read-only and offline zones cannot be written, do not >> + * mark them as sequential in the bitmap. >> + */ >> + list_length = get_unaligned_be32(&buf[0]) + 64; >> + rec = buf + 64; >> + buf_len = min(list_length, SD_ZBC_BUF_SIZE); >> + while (rec < buf + buf_len) { >> + type = rec[0] & 0x0f; >> + cond = (rec[1] >> 4) & 0xf; >> + if (type != ZBC_ZONE_TYPE_CONV && >> + cond != ZBC_ZONE_COND_READONLY && >> + cond != ZBC_ZONE_COND_OFFLINE) >> + set_bit(n, seq_zones); >> + block = get_unaligned_be64(&rec[8]) + >> + get_unaligned_be64(&rec[16]); >> + rec += 64; >> + n++; >> + } > > Split this out into a helper? Yes, that would be a nice cleanup. Will do. Thanks.
On Sun, Sep 24, 2017 at 05:07:01PM +0200, Christoph Hellwig wrote: > > +static inline unsigned long *sd_zbc_alloc_zone_bitmap(struct scsi_disk *sdkp) > > +{ > > + struct request_queue *q = sdkp->disk->queue; > > + > > + return kzalloc_node(BITS_TO_LONGS(sdkp->nr_zones) > > + * sizeof(unsigned long), > > + GFP_KERNEL, q->node); > > This really screams for kcalloc_node and friends that I think Johannes > volunteered to add. Thanks for the reminder, I'll send out the series today.
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c index 27793b9f54c0..50340c9d265b 100644 --- a/drivers/scsi/sd_zbc.c +++ b/drivers/scsi/sd_zbc.c @@ -586,8 +586,110 @@ static int sd_zbc_check_zone_size(struct scsi_disk *sdkp) return 0; } +/** + * sd_zbc_alloc_zone_bitmap - Allocate a zone bitmap (one bit per zone). + * @sdkp: The disk of the bitmap + */ +static inline unsigned long *sd_zbc_alloc_zone_bitmap(struct scsi_disk *sdkp) +{ + struct request_queue *q = sdkp->disk->queue; + + return kzalloc_node(BITS_TO_LONGS(sdkp->nr_zones) + * sizeof(unsigned long), + GFP_KERNEL, q->node); +} + +/** + * sd_zbc_setup_seq_zones - Initialize the disk request queue zone type bitmap. + * @sdkp: The disk of the bitmap + * + * Allocate a zone bitmap and initialize it by identifying sequential zones. + */ +static int sd_zbc_setup_seq_zones(struct scsi_disk *sdkp) +{ + struct request_queue *q = sdkp->disk->queue; + unsigned long *seq_zones; + sector_t block = 0; + unsigned char *buf; + unsigned char *rec; + unsigned int buf_len; + unsigned int list_length; + unsigned int n = 0; + u8 type, cond; + int ret = -ENOMEM; + + kfree(q->seq_zones); + q->seq_zones = NULL; + + seq_zones = sd_zbc_alloc_zone_bitmap(sdkp); + if (!seq_zones) + return -ENOMEM; + + buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL); + if (!buf) + goto out; + + while (block < sdkp->capacity) { + + ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, block); + if (ret) + goto out; + + /* + * Parse reported zone descriptors to find sequiential zones. + * Since read-only and offline zones cannot be written, do not + * mark them as sequential in the bitmap. + */ + list_length = get_unaligned_be32(&buf[0]) + 64; + rec = buf + 64; + buf_len = min(list_length, SD_ZBC_BUF_SIZE); + while (rec < buf + buf_len) { + type = rec[0] & 0x0f; + cond = (rec[1] >> 4) & 0xf; + if (type != ZBC_ZONE_TYPE_CONV && + cond != ZBC_ZONE_COND_READONLY && + cond != ZBC_ZONE_COND_OFFLINE) + set_bit(n, seq_zones); + block = get_unaligned_be64(&rec[8]) + + get_unaligned_be64(&rec[16]); + rec += 64; + n++; + } + + } + + if (n != sdkp->nr_zones) { + /* Something was wrong */ + ret = -EIO; + } + +out: + kfree(buf); + if (ret) { + kfree(seq_zones); + return ret; + } + + q->seq_zones = seq_zones; + + return 0; +} + +static void sd_zbc_cleanup(struct scsi_disk *sdkp) +{ + struct request_queue *q = sdkp->disk->queue; + + kfree(q->seq_zones); + q->seq_zones = NULL; + + kfree(sdkp->zones_wlock); + sdkp->zones_wlock = NULL; +} + static int sd_zbc_setup(struct scsi_disk *sdkp) { + struct request_queue *q = sdkp->disk->queue; + int ret; /* READ16/WRITE16 is mandatory for ZBC disks */ sdkp->device->use_16_for_rw = 1; @@ -599,14 +701,30 @@ static int sd_zbc_setup(struct scsi_disk *sdkp) sdkp->nr_zones = round_up(sdkp->capacity, sdkp->zone_blocks) >> sdkp->zone_shift; - if (!sdkp->zones_wlock) { - sdkp->zones_wlock = kcalloc(BITS_TO_LONGS(sdkp->nr_zones), - sizeof(unsigned long), - GFP_KERNEL); + /* + * Wait for the disk capacity to stabilize before + * initializing zone related information. + */ + if (sdkp->first_scan) + return 0; + + if (!sdkp->zones_wlock || q->nr_zones != sdkp->nr_zones) { + kfree(sdkp->zones_wlock); + sdkp->zones_wlock = sd_zbc_alloc_zone_bitmap(sdkp); if (!sdkp->zones_wlock) return -ENOMEM; } + if (!q->seq_zones || q->nr_zones != sdkp->nr_zones) { + ret = sd_zbc_setup_seq_zones(sdkp); + if (ret) { + sd_zbc_cleanup(sdkp); + return ret; + } + } + + q->nr_zones = sdkp->nr_zones; + return 0; } @@ -661,14 +779,14 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf) err: sdkp->capacity = 0; + sd_zbc_cleanup(sdkp); return ret; } void sd_zbc_remove(struct scsi_disk *sdkp) { - kfree(sdkp->zones_wlock); - sdkp->zones_wlock = NULL; + sd_zbc_cleanup(sdkp); } void sd_zbc_print_zones(struct scsi_disk *sdkp)
Initialize the seq_zones bitmap and nr_zones field of the disk request queue on disk revalidate. As the seq_zones bitmap allocation is identical to the allocation of the zone write lock bitmap, introduce the helper sd_zbc_alloc_zone_bitmap(). Using this helper, wait for the disk capacity and number of zones to stabilize on the second revalidation pass to allocate and initialize the bitmaps. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> --- drivers/scsi/sd_zbc.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 124 insertions(+), 6 deletions(-)