tree 9652a94ee8448bd3b1fa77d65711538d119f5fe9
parent d310eeef3f25c788546c885434292575fdf67663
author Maxim Dounin <mdounin@mdounin.ru> 1351595664 +0000
committer Maxim Dounin <mdounin@mdounin.ru> 1351595664 +0000

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.