mirror of
https://github.com/postgres/postgres.git
synced 2026-02-25 02:44:39 -05:00
43b491a817
Renaming a file using rename(2) is not guaranteed to be durable in face of crashes; especially on filesystems like xfs and ext4 when mounted with data=writeback. To be certain that a rename() atomically replaces the previous file contents in the face of crashes and different filesystems, one has to fsync the old filename, rename the file, fsync the new filename, fsync the containing directory. This sequence is not generally adhered to currently; which exposes us to data loss risks. To avoid having to repeat this arduous sequence, introduce durable_rename(), which wraps all that. Also add durable_link_or_rename(). Several places use link() (with a fallback to rename()) to rename a file, trying to avoid replacing the target file out of paranoia. Some of those rename sequences need to be durable as well. There seems little reason extend several copies of the same logic, so centralize the link() callers. This commit does not yet make use of the new functions; they're used in a followup commit. Author: Michael Paquier, Andres Freund Discussion: 56583BDD.9060302@2ndquadrant.com Backpatch: All supported branches |
||
|---|---|---|
| .. | ||
| backendid.h | ||
| barrier.h | ||
| block.h | ||
| buf.h | ||
| buf_internals.h | ||
| buffile.h | ||
| bufmgr.h | ||
| bufpage.h | ||
| checksum.h | ||
| checksum_impl.h | ||
| copydir.h | ||
| dsm.h | ||
| dsm_impl.h | ||
| fd.h | ||
| freespace.h | ||
| fsm_internals.h | ||
| indexfsm.h | ||
| ipc.h | ||
| item.h | ||
| itemid.h | ||
| itemptr.h | ||
| large_object.h | ||
| latch.h | ||
| lmgr.h | ||
| lock.h | ||
| lwlock.h | ||
| off.h | ||
| pg_sema.h | ||
| pg_shmem.h | ||
| pmsignal.h | ||
| pos.h | ||
| predicate.h | ||
| predicate_internals.h | ||
| proc.h | ||
| procarray.h | ||
| procsignal.h | ||
| reinit.h | ||
| relfilenode.h | ||
| s_lock.h | ||
| shm_mq.h | ||
| shm_toc.h | ||
| shmem.h | ||
| sinval.h | ||
| sinvaladt.h | ||
| smgr.h | ||
| spin.h | ||
| standby.h | ||