details: http://hg.nginx.org/nginx/rev/646985c55393
branches:
changeset: 6438:646985c55393
user: Maxim Dounin <mdounin@mdounin.ru>
date: Tue Mar 15 18:26:59 2016 +0300
description:
Truncation detection in sendfilev() on Solaris.

While sendfilev() is documented to return -1 with EINVAL set
if the file was truncated, at least Solaris 11 silently returns 0,
and this results in CPU hog. Added a test to complain appropriately
if 0 is returned.

diffstat:

src/os/unix/ngx_solaris_sendfilev_chain.c | 23 +++++++++++++++++++++++
1 files changed, 23 insertions(+), 0 deletions(-)

diffs (54 lines):

diff --git a/src/os/unix/ngx_solaris_sendfilev_chain.c b/src/os/unix/ngx_solaris_sendfilev_chain.c
--- a/src/os/unix/ngx_solaris_sendfilev_chain.c
+++ b/src/os/unix/ngx_solaris_sendfilev_chain.c
@@ -48,6 +48,7 @@ ngx_solaris_sendfilev_chain(ngx_connecti
ssize_t n;
ngx_int_t eintr;
ngx_err_t err;
+ ngx_buf_t *file;
ngx_uint_t nsfv;
sendfilevec_t *sfv, sfvs[NGX_SENDFILEVECS];
ngx_event_t *wev;
@@ -77,6 +78,7 @@ ngx_solaris_sendfilev_chain(ngx_connecti
fd = SFV_FD_SELF;
prev = NULL;
fprev = 0;
+ file = NULL;
sfv = NULL;
eintr = 0;
sent = 0;
@@ -153,6 +155,7 @@ ngx_solaris_sendfilev_chain(ngx_connecti
sfv->sfv_len = (size_t) size;
}

+ file = cl->buf;
fprev = cl->buf->file_pos + size;
send += size;
}
@@ -179,6 +182,26 @@ ngx_solaris_sendfilev_chain(ngx_connecti

ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
"sendfilev() sent only %uz bytes", sent);
+
+ } else if (n == 0 && sent == 0) {
+
+ /*
+ * sendfilev() is documented to return -1 with errno
+ * set to EINVAL if svf_len is greater than the file size,
+ * but at least Solaris 11 returns 0 instead
+ */
+
+ if (file) {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "sendfilev() reported that \"%s\" was truncated at %O",
+ file->file->name.data, file->file_pos);
+
+ } else {
+ ngx_log_error(NGX_LOG_ALERT, c->log, 0,
+ "sendfilev() returned 0 with memory buffers");
+ }
+
+ return NGX_CHAIN_ERROR;
}

ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,

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