diff options
| -rw-r--r-- | Config.in | 12 | ||||
| -rw-r--r-- | libbb/copyfd.c | 87 | ||||
| -rw-r--r-- | networking/Config.src | 8 | ||||
| -rw-r--r-- | networking/httpd.c | 6 |
4 files changed, 71 insertions, 42 deletions
@@ -264,6 +264,18 @@ config PAM Use PAM in some busybox applets (currently login and httpd) instead of direct access to password database. +config FEATURE_USE_SENDFILE + bool "Use sendfile system call" + default y + help + When enabled, busybox will use the kernel sendfile() function + instead of read/write loops to copy data between file descriptors + (for example, cp command does this a lot). + If sendfile() doesn't work, copying code falls back to read/write + loop. sendfile() was originally implemented for faster I/O + from files to sockets, but since Linux 2.6.33 it was extended + to work for many more file types. + config LONG_OPTS bool "Support for --long-options" default y diff --git a/libbb/copyfd.c b/libbb/copyfd.c index eda2747..7e35319 100644 --- a/libbb/copyfd.c +++ b/libbb/copyfd.c @@ -8,6 +8,20 @@ */ #include "libbb.h" +#if ENABLE_FEATURE_USE_SENDFILE +# include <sys/sendfile.h> +#else +# define sendfile(a,b,c,d) (-1) +#endif + +/* + * We were using 0x7fff0000 as sendfile chunk size, but it + * was seen to cause largish delays when user tries to ^C a file copy. + * Let's use a saner size. + * Note: needs to be >= max(CONFIG_FEATURE_COPYBUF_KB), + * or else "copy to eof" code will use neddlesly short reads. + */ +#define SENDFILE_BIGBUF (16*1024*1024) /* Used by NOFORK applets (e.g. cat) - must not use xmalloc. * size < 0 means "ignore write errors", used by tar --to-command @@ -18,12 +32,13 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) int status = -1; off_t total = 0; bool continue_on_write_error = 0; -#if CONFIG_FEATURE_COPYBUF_KB <= 4 + ssize_t sendfile_sz; +#if CONFIG_FEATURE_COPYBUF_KB > 4 + char *buffer = buffer; /* for compiler */ + int buffer_size = 0; +#else char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024]; enum { buffer_size = sizeof(buffer) }; -#else - char *buffer; - int buffer_size; #endif if (size < 0) { @@ -31,46 +46,58 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) continue_on_write_error = 1; } -#if CONFIG_FEATURE_COPYBUF_KB > 4 - if (size > 0 && size <= 4 * 1024) - goto use_small_buf; - /* We want page-aligned buffer, just in case kernel is clever - * and can do page-aligned io more efficiently */ - buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024, - PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANON, - /* ignored: */ -1, 0); - buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024; - if (buffer == MAP_FAILED) { - use_small_buf: - buffer = alloca(4 * 1024); - buffer_size = 4 * 1024; - } -#endif - if (src_fd < 0) goto out; + sendfile_sz = !ENABLE_FEATURE_USE_SENDFILE + ? 0 + : SENDFILE_BIGBUF; if (!size) { - size = buffer_size; + size = SENDFILE_BIGBUF; status = 1; /* copy until eof */ } while (1) { ssize_t rd; - rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size); - - if (!rd) { /* eof - all done */ - status = 0; - break; + if (sendfile_sz) { + rd = sendfile(dst_fd, src_fd, NULL, + size > sendfile_sz ? sendfile_sz : size); + if (rd >= 0) + goto read_ok; + sendfile_sz = 0; /* do not try sendfile anymore */ + } +#if CONFIG_FEATURE_COPYBUF_KB > 4 + if (buffer_size == 0) { + if (size > 0 && size <= 4 * 1024) + goto use_small_buf; + /* We want page-aligned buffer, just in case kernel is clever + * and can do page-aligned io more efficiently */ + buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, + /* ignored: */ -1, 0); + buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024; + if (buffer == MAP_FAILED) { + use_small_buf: + buffer = alloca(4 * 1024); + buffer_size = 4 * 1024; + } } +#endif + rd = safe_read(src_fd, buffer, + size > buffer_size ? buffer_size : size); if (rd < 0) { bb_perror_msg(bb_msg_read_error); break; } + read_ok: + if (!rd) { /* eof - all done */ + status = 0; + break; + } /* dst_fd == -1 is a fake, else... */ - if (dst_fd >= 0) { + if (dst_fd >= 0 && !sendfile_sz) { ssize_t wr = full_write(dst_fd, buffer, rd); if (wr < rd) { if (!continue_on_write_error) { @@ -92,10 +119,8 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) } out: -#if CONFIG_FEATURE_COPYBUF_KB > 4 - if (buffer_size != 4 * 1024) + if (buffer_size > 4 * 1024) munmap(buffer, buffer_size); -#endif return status ? -1 : total; } diff --git a/networking/Config.src b/networking/Config.src index e566469..15a6968 100644 --- a/networking/Config.src +++ b/networking/Config.src @@ -181,14 +181,6 @@ config FEATURE_HTTPD_RANGES "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted downloads, seeking in multimedia players etc. -config FEATURE_HTTPD_USE_SENDFILE - bool "Use sendfile system call" - default y - depends on HTTPD - help - When enabled, httpd will use the kernel sendfile() function - instead of read/write loop. - config FEATURE_HTTPD_SETUID bool "Enable -u <user> option" default y diff --git a/networking/httpd.c b/networking/httpd.c index 621d9cd..9cf0804 100644 --- a/networking/httpd.c +++ b/networking/httpd.c @@ -133,7 +133,7 @@ # include <security/pam_appl.h> # include <security/pam_misc.h> #endif -#if ENABLE_FEATURE_HTTPD_USE_SENDFILE +#if ENABLE_FEATURE_USE_SENDFILE # include <sys/sendfile.h> #endif /* amount of buffering in a pipe */ @@ -1624,7 +1624,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what) #endif if (what & SEND_HEADERS) send_headers(HTTP_OK); -#if ENABLE_FEATURE_HTTPD_USE_SENDFILE +#if ENABLE_FEATURE_USE_SENDFILE { off_t offset = range_start; while (1) { @@ -1654,7 +1654,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what) break; } if (count < 0) { - IF_FEATURE_HTTPD_USE_SENDFILE(fin:) + IF_FEATURE_USE_SENDFILE(fin:) if (verbose > 1) bb_perror_msg("error"); } |