PHP POST 接受长字符串时出现 500 错误
今天发布 typecho 文章出现 500 错误，字符串短没有任何问题，长文章直接报错 500 Internal Server Error。
查看 nginx 错误日志 /var/log/nginx/error.log 发现以下错误信息：
2023/07/06 12:40:08 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000004" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
2023/07/06 12:41:43 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000005" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
2023/07/06 12:42:26 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000006" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
2023/07/06 12:42:40 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000007" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
2023/07/06 12:43:11 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000008" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
2023/07/06 12:44:35 [crit] 15896#0: *2125 open() "/var/lib/nginx/tmp/client_body/0000000009" failed (13: Permission denied), client: 119.147.10.212, server: imx.ink, request: "POST /action/contents-post-edit?_=8679a495ae30a8c84ff2fc1fccb8a4e7 HTTP/2.0", host: "imx.ink", referrer: "https://imx.ink/admin/write-post.php?cid=42"
进到 /var/lib 目录下查看 nginx 目录的权限：
$ ls -al /var/lib
drwx------ 3 root root 4096 Jun 13 12:50 nginx
执行命令 chmod -R 775 /var/lib/nginx 问题解决。