From 37264b237cee5c29691047ce0dffd0f57dccf463 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Wed, 9 Apr 2014 09:50:46 -0700 Subject: [PATCH] s3: smbd: Performance optimization for RECVFILE. Based on work proposed by Jones . Removes set_blocking()/set_unblocking() fcntl calls around RECVFILE on the non-blocking socket. Instead uses RECVFILE in a loop, and only drops back to set_blocking()/set_unblocking() once RECVFILE returns -1/EAGAIN/EWOULDBLOCK. From the samba-technical list: ------------------------------------------------ The iometer 512b sequential write shows following result, Before applying this patch: 75333 IOps After applying this patch: 82691 IOps ------------------------------------------------ Signed-off-by: Jeremy Allison --- source3/smbd/vfs.c | 56 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 13 deletions(-) diff --git a/source3/smbd/vfs.c b/source3/smbd/vfs.c index bc9157a..897bf1f3 100644 --- a/source3/smbd/vfs.c +++ b/source3/smbd/vfs.c @@ -473,24 +473,54 @@ ssize_t vfs_pwrite_data(struct smb_request *req, if (req && req->unread_bytes) { int sockfd = req->sconn->sock; - int old_flags; SMB_ASSERT(req->unread_bytes == N); /* VFS_RECVFILE must drain the socket * before returning. */ req->unread_bytes = 0; - /* Ensure the socket is blocking. */ - old_flags = fcntl(sockfd, F_GETFL, 0); - if (set_blocking(sockfd, true) == -1) { - return (ssize_t)-1; - } - ret = SMB_VFS_RECVFILE(sockfd, - fsp, - offset, - N); - if (fcntl(sockfd, F_SETFL, old_flags) == -1) { - return (ssize_t)-1; + /* + * Leave the socket non-blocking and + * use SMB_VFS_RECVFILE. If it returns + * EAGAIN || EWOULDBLOCK temporarily set + * the socket blocking and retry + * the RECVFILE. + */ + while (total < N) { + ret = SMB_VFS_RECVFILE(sockfd, + fsp, + offset + total, + N - total); +#if defined(EWOULDBLOCK) + if (ret == 0 || (ret == -1 && + (errno == EAGAIN || errno == EWOULDBLOCK))) { +#else /* EWOULDBLOCK */ + if (ret == 0 || (ret == -1 && errno == EAGAIN)) { +#endif /* EWOULDBLOCK */ + int old_flags; + /* Ensure the socket is blocking. */ + old_flags = fcntl(sockfd, F_GETFL, 0); + if (set_blocking(sockfd, true) == -1) { + return (ssize_t)-1; + } + ret = SMB_VFS_RECVFILE(sockfd, + fsp, + offset + total, + N - total); + if (fcntl(sockfd, F_SETFL, old_flags) == -1) { + return (ssize_t)-1; + } + if (ret == -1) { + return (ssize_t)-1; + } + total += ret; + return (ssize_t)total; + } + /* Any other error case. */ + if (ret == -1) { + return ret; + } + total += ret; } - return ret; + return (ssize_t)total; } while (total < N) { -- 1.9.1.423.g4596e3a