Re: [Libguestfs] [nbdkit PATCH] connections: Extract common export flag computation code

No need to duplicate maintenance of export flag computation between old and new style handshakes. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/connections.c | 120 +++++++++++++++++++++--------------------------------- 1 file changed, 47 insertions(+), 73 deletions(-) diff --git a/src/connections.c b/src/connections.c index 8dc1925..f9edea7 100644 --- a/src/connections.c +++ b/src/connections.c @@ -237,13 +237,57 @@ free_connection (struct connection *conn) } static int +compute_eflags (struct connection *conn, uint16_t *flags) +{ + uint16_t eflags = NBD_FLAG_HAS_FLAGS; + int fl; + + fl = plugin_can_write (conn); + if (fl == -1) + return -1; + if (readonly || !fl) { + eflags |= NBD_FLAG_READ_ONLY; + conn->readonly = 1; + } + if (!conn->readonly) { + eflags |= NBD_FLAG_SEND_WRITE_ZEROES; + } + + fl = plugin_can_flush (conn); + if (fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA; + conn->can_flush = 1; + } + + fl = plugin_is_rotational (conn); + if (fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_ROTATIONAL; + conn->is_rotational = 1; + } + + fl = plugin_can_trim (conn); + if (fl == -1) + return -1; + if (fl) { + eflags |= NBD_FLAG_SEND_TRIM; + conn->can_trim = 1; + } + + *flags = eflags; + return 0; +} + +static int _negotiate_handshake_oldstyle (struct connection *conn) { struct old_handshake handshake; int64_t r; uint64_t exportsize; uint16_t gflags, eflags; - int fl; /* In --tls=require / FORCEDTLS mode, old style handshakes are * rejected because they cannot support TLS. @@ -265,43 +309,8 @@ _negotiate_handshake_oldstyle (struct connection *conn) conn->exportsize = exportsize; gflags = 0; - eflags = NBD_FLAG_HAS_FLAGS; - - fl = plugin_can_write (conn); - if (fl == -1) + if (compute_eflags (conn, &eflags) < 0) return -1; - if (readonly || !fl) { - eflags |= NBD_FLAG_READ_ONLY; - conn->readonly = 1; - } - if (!conn->readonly) { - eflags |= NBD_FLAG_SEND_WRITE_ZEROES; - } - - - fl = plugin_can_flush (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA; - conn->can_flush = 1; - } - - fl = plugin_is_rotational (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_ROTATIONAL; - conn->is_rotational = 1; - } - - fl = plugin_can_trim (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_SEND_TRIM; - conn->can_trim = 1; - } debug ("oldstyle negotiation: flags: global 0x%x export 0x%x", gflags, eflags); @@ -552,7 +561,6 @@ _negotiate_handshake_newstyle (struct connection *conn) int64_t r; uint64_t exportsize; uint16_t eflags; - int fl; gflags = NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES; @@ -596,42 +604,8 @@ _negotiate_handshake_newstyle (struct connection *conn) exportsize = (uint64_t) r; conn->exportsize = exportsize; - eflags = NBD_FLAG_HAS_FLAGS; - - fl = plugin_can_write (conn); - if (fl == -1) + if (compute_eflags (conn, &eflags) < 0) return -1; - if (readonly || !fl) { - eflags |= NBD_FLAG_READ_ONLY; - conn->readonly = 1; - } - if (!conn->readonly) { - eflags |= NBD_FLAG_SEND_WRITE_ZEROES; - } - - fl = plugin_can_flush (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA; - conn->can_flush = 1; - } - - fl = plugin_is_rotational (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_ROTATIONAL; - conn->is_rotational = 1; - } - - fl = plugin_can_trim (conn); - if (fl == -1) - return -1; - if (fl) { - eflags |= NBD_FLAG_SEND_TRIM; - conn->can_trim = 1; - } debug ("newstyle negotiation: flags: export 0x%x", eflags);