diff options
| author | Wouter Verhelst <w@uter.be> | 2024-08-12 15:20:37 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-09-06 08:31:40 -0600 |
| commit | e49dacc71ec2621ce4c422cd5605d4d06f7807b0 (patch) | |
| tree | 20bb6fa265e1670c83c5275d212ddc0a2e1e50b0 | |
| parent | f55d3b82ac2fe8e12fe784702a7a39ab36b7d4e1 (diff) | |
nbd: implement the WRITE_ZEROES command
The NBD protocol defines a message for zeroing out a region of an export
Add support to the kernel driver for that message.
Signed-off-by: Wouter Verhelst <w@uter.be>
Cc: Eric Blake <eblake@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240812133032.115134-3-w@uter.be
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/nbd.c | 8 | ||||
| -rw-r--r-- | include/uapi/linux/nbd.h | 5 |
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 4d06472bf112..eee632b84994 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -363,6 +363,8 @@ static int __nbd_set_size(struct nbd_device *nbd, loff_t bytesize, } if (nbd->config->flags & NBD_FLAG_ROTATIONAL) lim.features |= BLK_FEAT_ROTATIONAL; + if (nbd->config->flags & NBD_FLAG_SEND_WRITE_ZEROES) + lim.max_write_zeroes_sectors = UINT_MAX >> SECTOR_SHIFT; lim.logical_block_size = blksize; lim.physical_block_size = blksize; @@ -432,6 +434,8 @@ static u32 req_to_nbd_cmd_type(struct request *req) return NBD_CMD_WRITE; case REQ_OP_READ: return NBD_CMD_READ; + case REQ_OP_WRITE_ZEROES: + return NBD_CMD_WRITE_ZEROES; default: return U32_MAX; } @@ -648,6 +652,8 @@ static blk_status_t nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, if (req->cmd_flags & REQ_FUA) nbd_cmd_flags |= NBD_CMD_FLAG_FUA; + if ((req->cmd_flags & REQ_NOUNMAP) && (type == NBD_CMD_WRITE_ZEROES)) + nbd_cmd_flags |= NBD_CMD_FLAG_NO_HOLE; /* We did a partial send previously, and we at least sent the whole * request struct, so just go and send the rest of the pages in the @@ -1717,6 +1723,8 @@ static int nbd_dbg_flags_show(struct seq_file *s, void *unused) seq_puts(s, "NBD_FLAG_SEND_FUA\n"); if (flags & NBD_FLAG_SEND_TRIM) seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); + if (flags & NBD_FLAG_SEND_WRITE_ZEROES) + seq_puts(s, "NBD_FLAG_SEND_WRITE_ZEROES\n"); return 0; } diff --git a/include/uapi/linux/nbd.h b/include/uapi/linux/nbd.h index d75215f2c675..f1d468acfb25 100644 --- a/include/uapi/linux/nbd.h +++ b/include/uapi/linux/nbd.h @@ -42,8 +42,9 @@ enum { NBD_CMD_WRITE = 1, NBD_CMD_DISC = 2, NBD_CMD_FLUSH = 3, - NBD_CMD_TRIM = 4 + NBD_CMD_TRIM = 4, /* userspace defines additional extension commands */ + NBD_CMD_WRITE_ZEROES = 6, }; /* values for flags field, these are server interaction specific. */ @@ -53,11 +54,13 @@ enum { #define NBD_FLAG_SEND_FUA (1 << 3) /* send FUA (forced unit access) */ #define NBD_FLAG_ROTATIONAL (1 << 4) /* device is rotational */ #define NBD_FLAG_SEND_TRIM (1 << 5) /* send trim/discard */ +#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* supports WRITE_ZEROES */ /* there is a gap here to match userspace */ #define NBD_FLAG_CAN_MULTI_CONN (1 << 8) /* Server supports multiple connections per export. */ /* values for cmd flags in the upper 16 bits of request type */ #define NBD_CMD_FLAG_FUA (1 << 16) /* FUA (forced unit access) op */ +#define NBD_CMD_FLAG_NO_HOLE (1 << 17) /* Do not punch a hole for WRITE_ZEROES */ /* These are client behavior specific flags. */ #define NBD_CFLAG_DESTROY_ON_DISCONNECT (1 << 0) /* delete the nbd device on |