From f462e8f913bdc7a28ce55508d0c045a0c445b157 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Fri, 24 Feb 2006 13:03:57 -0800 Subject: [PATCH] [PATCH] uml: better error reporting for read_output Do precise error handling: print precise error messages, distinguishing short reads and read errors. This functions fails frequently enough for me so I bothered doing this fix. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Acked-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/drivers/net_user.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c index 098fa65981..0e2f06187e 100644 --- a/arch/um/drivers/net_user.c +++ b/arch/um/drivers/net_user.c @@ -47,10 +47,12 @@ void tap_check_ips(char *gate_addr, unsigned char *eth_addr) } } +/* Do reliable error handling as this fails frequently enough. */ void read_output(int fd, char *output, int len) { - int remain, n, actual; + int remain, ret, expected; char c; + char *str; if(output == NULL){ output = &c; @@ -58,23 +60,31 @@ void read_output(int fd, char *output, int len) } *output = '\0'; - n = os_read_file(fd, &remain, sizeof(remain)); - if(n != sizeof(remain)){ - printk("read_output - read of length failed, err = %d\n", -n); - return; + ret = os_read_file(fd, &remain, sizeof(remain)); + + if (ret != sizeof(remain)) { + expected = sizeof(remain); + str = "length"; + goto err; } while(remain != 0){ - n = (remain < len) ? remain : len; - actual = os_read_file(fd, output, n); - if(actual != n){ - printk("read_output - read of data failed, " - "err = %d\n", -actual); - return; + expected = (remain < len) ? remain : len; + ret = os_read_file(fd, output, expected); + if (ret != expected) { + str = "data"; + goto err; } - remain -= actual; + remain -= ret; } + return; + +err: + if (ret < 0) + printk("read_output - read of %s failed, errno = %d\n", str, -ret); + else + printk("read_output - read of %s failed, read only %d of %d bytes\n", str, ret, expected); } int net_read(int fd, void *buf, int len) -- 2.39.5