diff options
Diffstat (limited to 'include/uapi/linux/nbd.h')
| -rw-r--r-- | include/uapi/linux/nbd.h | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/include/uapi/linux/nbd.h b/include/uapi/linux/nbd.h index 20d6cc91435d..f1d468acfb25 100644 --- a/include/uapi/linux/nbd.h +++ b/include/uapi/linux/nbd.h @@ -11,6 +11,8 @@ * Cleanup PARANOIA usage & code. * 2004/02/19 Paul Clements * Removed PARANOIA, plus various cleanup and comments + * 2023 Copyright Red Hat + * Link to userspace extensions, favor cookie over handle. */ #ifndef _UAPILINUX_NBD_H @@ -30,12 +32,19 @@ #define NBD_SET_TIMEOUT _IO( 0xab, 9 ) #define NBD_SET_FLAGS _IO( 0xab, 10) +/* + * See also https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md + * for additional userspace extensions not yet utilized in the kernel module. + */ + enum { NBD_CMD_READ = 0, 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. */ @@ -43,12 +52,15 @@ enum { #define NBD_FLAG_READ_ONLY (1 << 1) /* device is read-only */ #define NBD_FLAG_SEND_FLUSH (1 << 2) /* can flush writeback cache */ #define NBD_FLAG_SEND_FUA (1 << 3) /* send FUA (forced unit access) */ -/* there is a gap here to match userspace */ +#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 @@ -64,15 +76,19 @@ enum { #define NBD_REQUEST_MAGIC 0x25609513 #define NBD_REPLY_MAGIC 0x67446698 /* Do *not* use magics: 0x12560953 0x96744668. */ +/* magic 0x668e33ef for structured reply not supported by kernel yet */ /* * This is the packet used for communication between client and * server. All data are in network byte order. */ struct nbd_request { - __be32 magic; - __be32 type; /* == READ || == WRITE */ - char handle[8]; + __be32 magic; /* NBD_REQUEST_MAGIC */ + __be32 type; /* See NBD_CMD_* */ + union { + __be64 cookie; /* Opaque identifier for request */ + char handle[8]; /* older spelling of cookie */ + }; __be64 from; __be32 len; } __attribute__((packed)); @@ -82,8 +98,11 @@ struct nbd_request { * it has completed an I/O request (or an error occurs). */ struct nbd_reply { - __be32 magic; + __be32 magic; /* NBD_REPLY_MAGIC */ __be32 error; /* 0 = ok, else error */ - char handle[8]; /* handle you got from request */ + union { + __be64 cookie; /* Opaque identifier from request */ + char handle[8]; /* older spelling of cookie */ + }; }; #endif /* _UAPILINUX_NBD_H */ |