tree 2759f5ccd171607a9b8ef3be7d526c62eb66921e
parent 1954cf149aa79ba2bb1ce0b7b20422ab2ca6c93a
author Maxim Dounin <mdounin@mdounin.ru> 1352805854 +0000
committer Maxim Dounin <mdounin@mdounin.ru> 1352805854 +0000

Merge of r4896: event pipe: fixed handling of buf_to_file data.

Input filter might free a buffer if there is no data in it, and in case
of first buffer (used for cache header and request header, aka p->buf_to_file)
this resulted in cache corruption.  Buffer memory was reused to read upstream
response before headers were written to disk.

Fix is to avoid moving pointers in ngx_event_pipe_add_free_buf() to a buffer
start if we were asked to free a buffer used by p->buf_to_file.

This fixes occasional cache file corruption, usually resulted
in "cache file ... has md5 collision" alerts.

Reported by Anatoli Marinov.